Good Article
Profiler
More on Gluten
Detecting Celiac Disease in Your Patients
HAROLD T. PRUESSNER, M.D.,
University of Texas Medical School at Houston
A patient information handout on celiac disease, written by the author of
this article, is provided on page 1039.
Celiac disease is a genetic, immunologically mediated small bowel
enteropathy that causes malabsorption. The immune inflammatory response to
gluten frequently causes damage to many other tissues of the body. The
condition is frequently underdiagnosed because of its protean
presentations. New prevalence data indicate that symptomatic and latent
celiac disease is present in one of 300 people of European descent. Age of
onset ranges from infancy to old age. Symptomatic presentations include
general ill-health, as well as dermatologic...
Randall
> http://www.aafp.org/afp/980301ap/pruessn.html
Hi,
Thanks for a good link.
Here is some more info to digest in light of LPS and
proteins and IMID's.
Do dietary lectins cause disease?
http://www.bmj.com/cgi/content/full/318/7190/1023
http://groups.google.com/groups?q=don+wiss+group:alt.support.skin-diseases.psoriasis&hl=en&lr=&ie=UTF-8&oe=UTF-8&selm=df7e2c67.0206071642.308d5ef7%40posting.google.com&rnum=3
If you do a search on www.deja.com for Don Wiss in the P newsgroup
you'll get around 60 hits. His site is Don <www.gluten-free.org>.
More important is the LPS generated by the bad gut flora that
modulates immunity and upregulates cytokines, interleukins et al.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12378124&dopt=Abstract
Immune reactivity to DPs may be associated with apparent DPI and GI
inflammation in ASD children that may be partly associated with
aberrant innate immune response against endotoxin, a product of the
gut bacteria.
If you use the empty search box in the above pubmed abstract and
keyword (LPS) you'll get over 40,000 hits, use gliaden for 1500 hits.
You can use any keyword in combo with the above such as (lps and
gliadin)
and you'll get one hit!
This will change as this complex is increasingly studied.
Seems like the IMID autism shares something in common with P.
The same imflammatory agents for one! This is where the multifactorial
part of P comes in. The P crud ends up on our skin and for autism
wreaks havoc with their entire being. And if P is compensatory for
the ill effects of the auto immune system due to absorbed LPS from
endogenous gut bacteria that is shunted by an overworked liver into
the lymphatics then www.thewholewhey.com is the most logical whey to
block the translocation of bacteria into the system.
YOU, profiler need to first understand LPS and LBP.
Here is a deja search on keywords randall,lps and ncbi on the P ng.
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&threadm=df7e2c67.0209290954.12bb1979%40posting.google.com&rnum=1&prev=/groups%3Fhl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26q%3Drandall%2BLPS%2Bncbi%26btnG%3DGoogle%2BSearch%26meta%3Dgroup%253Dalt.support.skin-diseases.psoriasis
And if that doesn't do it for you i suggest you read the Xoma link
to Bacterial endotoxins in Human Disease.
http://www.xoma.com/sci/kpmgendo.pdf
You do need an acrobat reader for this one. Or download onto
a disk and read it five times till it starts to sink in. As its
written in 1999 the science has marched on and many good abstracts
on LPS are found in the above searches of mine.
I hope this gets your spine straight. :)
randall... more on LPS, one more time.
notagain
Thanks also for the links. I thought that this was an interesting bit in
the following article link you posted.
http://bmj.com/cgi/content/full/318/7190/1023
"Many lectins are powerful allergens, and prohevein, the principal allergen
of rubber latex, is one. It has been engineered into transgenic tomatoes for
its fungistatic properties,18 so we can expect an outbreak of tomato allergy
in the near future among latex sensitive individuals. Dr Arpad Pusztai lost
his job for publicising concerns of this type (20 February, p 483)".
"Randall" <ranh...@aol.com> wrote in message
news:df7e2c67.02112...@posting.google.com...
JXStern
<nota...@spamspamspam.co.uk> wrote:
>http://bmj.com/cgi/content/full/318/7190/1023
>"Many lectins are powerful allergens, and prohevein, the principal allergen
>of rubber latex, is one. It has been engineered into transgenic tomatoes for
>its fungistatic properties,18 so we can expect an outbreak of tomato allergy
>in the near future among latex sensitive individuals. Dr Arpad Pusztai lost
>his job for publicising concerns of this type (20 February, p 483)".
Yikes.
J.
DaveW
It's kind of a shame that Michaelsson's work on gluten intolerance in psoriasis
patients didn't really show sginificant results until two years after this
article was published. I think it would have been interesting to read
Pruessner put that research in perspective with the rest.
Whaddaya think, Randall? I know Michaelsson's a fave of yours, in a way.
[grin]
- Dave W.
http://psorsite.com/
Profiler
> http://www.xoma.com/sci/kpmgendo.pdf
Bookmarked the gluten free site
this pdf wouldn't load for me - could someone post it here as an
attachment please?
DaveW
>> http://www.xoma.com/sci/kpmgendo.pdf
>
>this pdf wouldn't load for me - could someone post it here as an
>attachment please?
The server says that that file does not exist.
Dave
"DaveW" <stran...@aol.com> wrote in message
news:20021128102359...@mb-df.aol.com...
Is this what you were looking for?.....
This is the html version of the file http://www.xoma.com/sci/kpmgendo.pdf.
G o o g l e automatically generates html versions of documents as we crawl
the web.
To link to or bookmark this page, use the following url:
http://www.google.com/search?q=cache:r4m2LGdCjfYC:www.xoma.com/sci/
kpmgendo.pdf+kpmgendo.pdf&hl=en&ie=UTF-8
Google is not affiliated with the authors of this page nor responsible for
its content.
These terms only appear in links pointing to this page: kpmgendo pdf
Page 1
Bacterial Endotoxin
in Human Disease
I
How advances in understanding the role
of Gram-negative bacteria and endotoxin
in infectious diseases and complications
may improve the development
of diagnostic and treatment options
Michael H. Silverman, MD, FACP
Marc J. Ostro, PhD
Page 2
* Death
Heart Disease
Burns
Other
Digestive
System
Diseases
Cardiovascular
Surgery
Meningococcemia
Respiratory
Disease
Renal
Disease
Cancer
Autoimmune
Diseases
Infections
* Shock/MODS
2
* Sepsis
* SIRS
1
* Bacteria/Endotoxin
* At Risk
* Healthy
1 Systemic Inflammatory
Response Syndrome
2 Multiple Organ Dysfunction
Syndrome
Trauma
Figure 1: A Model for Diseases Potentially Associated with
Bacteria/Endotoxin
© 1998 XOMA Ltd.
Page 3
i
Gram-negative bacteria and their endotoxins may be a causal or complicating
factor in many serious diseases. The syndromes most commonly connected with
bacterial endotoxins are sepsis and septic shock, which are systemic
complica-
tions of many diseases. Systemic infections (septicemias) caused by invasive
Gram-negative bacteria are a well known source of endotoxin exposure. Less
well-recognized, although perhaps of greater importance, are infectious
complica-
tions (such as those following trauma or surgery) that may be initiated by
expo-
sure to endogenous Gram-negative intestinal bacteria.
Whatever the source, exposure to endotoxin induces a systemic inflammatory
response (also called the inflammatory or sepsis cascade) that involves many
interconnected cellular and plasma mediators. The inflammatory response
mani-
fests in such clinical signs as fever, increased heart and respiratory
rates, and
other systemic symptoms. These may be self-limiting, or the cascade can
proceed
to shock, organ failure and death. Currently available treatment efforts are
limited
to antibiotics and, in serious cases, supportive intensive medical care.
Advancements in efforts to prevent or treat the systemic inflammatory
response
to endotoxin have been hampered by several factors. The lack of a consistent
and
rapid diagnostic for endotoxin exposure is one. The choice of a
clinically-relevant
therapeutic target is another. Halting the ongoing endotoxin stimulation of
the
inflammatory response at the source would seem to be more effective than
inhibiting any individual component. Nevertheless, most investigational
therapies
have targeted individual mediators within the inflammatory cascade. A third
fac-
tor is the conceptual lock that sepsis has had on pharmaceutical
development. In
the past eight years, at least 13 different products have failed to show the
required survival benefit in sepsis trials. Surprisingly, these failures
have, with
rare exceptions, not stimulated radical change in pharmaceutical companies'
or
regulators' approach to clinical trial design or disease targets.
This paper challenges the current understanding in this field. In the old
model,
sepsis was viewed as a unique clinical syndrome, difficult to treat, but the
obvi-
ous target for therapy. The new model (see Figure 1) incorporates sepsis,
but as a
late-stage syndrome on a continuum of endotoxin-related diseases. The new
map
encompasses the entire inflammatory cascade and its clinical manifestations.
Understanding such a new paradigm may open the way to improved diagnostic
and therapeutic approaches that can identify at-risk patients and treat them
at the
appropriate stage in the inflammatory process, within the context of each
patient's underlying disease.
Preface
Page 4
ii
Summary
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . iii
I. Introduction
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . 1
A. Medical Importance of Endotoxin
B. Terminology and Approach
II. Basic Biology of Endotoxin
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . 2
A. General Features
B. Circulating Endotoxin
III. Pathophysiology of the Endotoxin-Induced Inflammatory Response
. . . . . . 4
A. Routes of Exposure to Endotoxin
B. Host Interactions with Endotoxin
C. Summary: Pathogenesis of the Inflammatory Cascade
D. Diagnostic and Prognostic Markers of SIRS and Sepsis
IV. Endotoxin-Related Clinical Syndromes
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
A. Sepsis, Septic Shock and SIRS
B. Meningococcemia
V. Other Clinical Conditions
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . 14
A. Complications That May Be Associated with Gut Translocation
B. Local and Organ-Specific Diseases
VI. Current Treatment of Sepsis
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 18
VII. Future Directions in the Treatment of Sepsis and Septic Shock
. . . . . . . . . 19
VIII. Conclusion: Beyond Sepsis
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . 20
Glossary
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . 21
References
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . 23
Table of Contents
Page 5
iii
* Endotoxins are complex lipopolysaccharides (LPS),
major cell wall components in all Gram-negative bacte-
ria. LPS has two regions: polysaccharide and lipid A.
Lipid A, highly conserved across bacterial families, is
the primary toxic component.
* Endotoxin can enter the blood (causing endotoxemia) in
two ways: 1) through local or systemic infection by
exogenous Gram-negative bacteria, and 2) by transloca-
tion of endogenous Gram-negative bacteria or fragments
across the intestinal membrane when permeability is
increased following systemic insults such as trauma.
* Circulating endotoxin can induce an overwhelming
inflammatory host response (the "systemic inflammatory
response" or "sepsis cascade"). Mediated initially by
LPS binding to lipopolysaccharide binding protein
(LBP), the LBP-LPS complex stimulates reactions from
immune system and tissue cells and activates various
interrelated non-cellular cascades. The resulting clinical
syndrome is known as "sepsis" when an infection can be
detected (e.g., meningococcemia), and as the systemic
inflammatory response syndrome (SIRS) in the absence
of documented infection.
* Sepsis can progress to septic shock, a catastrophic syn-
drome characterized by refractory hypotension and
multiple organ failure. With perhaps half a million
patients annually affected in the U.S., fatality rates of up
to 40%, and no approved pharmaceutical therapy, sepsis
and septic shock remain a significant and growing
unmet medical need.
* Endotoxin has also been associated with a myriad of
diseases and syndromes although its clinical significance
is not always clear. Examples include: complications
associated with trauma, burns and invasive surgery, as
well as organ-specific illnesses such as cystic fibrosis,
inflammatory bowel disease, liver disease, kidney dialy-
sis complications, asthma and autoimmune diseases.
* Technical and biological hurdles have prevented the
development of reliable diagnostic tests for endotoxin.
Outside of Japan, there is no approved diagnostic for
endotoxemia. Even reliable tests might not detect tran-
sient but clinically-significant endotoxin exposure. The
absence of good diagnostics has hampered the clinical
development of therapeutic agents.
* The current treatment of septic complications is imme-
diate resuscitation and administration of antibiotics, fol-
lowed by stabilization and support of vital functions.
There are no predictably effective pharmaceutical inter-
ventions for sepsis, probably in large part because it is a
complication of so many different underlying diseases.
* Nevertheless, over the past decade, many products have
been clinically tested in heterogeneous populations of
sepsis and septic shock patients. None have succeeded.
Despite the previous unsuccessful attempts, new thera-
peutic candidates continue to enter the clinic. As of this
writing, at least a dozen Phase II and III clinical trials
are underway for therapies targeting established or sus-
pected sepsis mediators. Most of these therapies are
directed at specific components of the sepsis cascade.
* Given what we now know about the inflammatory cas-
cade, a more fruitful avenue of development could be to
target endotoxin within the context of the underlying
disease. In addition to targeting better characterized
diseases, clinical trials could also focus on preventing,
rather than treating, septic complications. A few agents
now in clinical trials are indeed following this approach.
* A historical legacy of confusing terminology has imped-
ed communication in this area. An American College of
Chest Physicians Consensus Conference in 1992 clari-
fied clinical definitions of sepsis and septic shock, but
to date there is still no generally-accepted scientific ter-
minology to describe the full landscape of endotoxin-
associated disorders.
Summary
Page 6
1
I.
Introduction
A. Medical Importance of Endotoxin
Endotoxins are high-molecular weight complexes of
lipopolysaccharides (LPS) that constitute the major cell
wall component in all Gram-negative bacterial families
(McCuskey). These molecules have been intensively inves-
tigated because of the increasing appreciation of their
potentially pathogenic role in a wide variety of human
disease states (Rietschel).
For example, endotoxin is now believed to be the primary
trigger of Gram-negative septic shock, a catastrophic and
frequently fatal systemic syndrome characterized by
hypotension, inadequate organ perfusion and multiple organ
failure. Sepsis and septic shock, which have been increasing
in prevalence since the 1950s (ACCP, Glauser), cause an
estimated 175,000-200,000 deaths annually in the United
States (Hoffman, Ulevitch). The syndrome has been associ-
ated with Gram-negative bacterial infection and, therefore,
with endotoxin, in 30 to 80% of patients in recent large
studies (Glauser). The lack of a documented infection does
not, however, exclude the possibility of endotoxemia
induced by undetected Gram-negative bacteria.
Despite advances in medical therapy, sepsis carries a mor-
tality rate of 10-15% in children and up to 40% in adults
(Carcillo). According to the Centers for Disease Control
and Prevention (CDC), septicemia (the term CDC uses) is
the 12th leading cause of death in the United States.
Nationwide, sepsis is estimated to cost $5-10 billion annu-
ally (Bone). Septic shock is the leading cause of death in
hospital intensive care units, where the incidence is often
2-5 times higher than in other hospital departments
(Gasche). The incidence of sepsis and its associated mor-
bidity and mortality is rising with the growing use of inva-
sive techniques, immunosuppression and cytotoxic
chemotherapy, and concomitant increases in nosocomial
infections (Lamy).
Bacterial endotoxin can enter the bloodstream, causing
endotoxemia, in two ways. The most well-recognized is
infection by exogenous Gram-negative bacteria (infection
from without). The second potential source is the popula-
tion of endogenous Gram-negative bacteria that inhabit the
gastrointestinal tract (infection from within). The transloca-
tion hypothesis postulates that in a wide variety of surgical
and medical situations, gut bacteria and their endotoxins
leak through an abnormally permeable intestinal wall
(Deitch, Hecht, van Leeuwen) and enter the bloodstream.
Translocation has been demonstrated in various animal
models and is implicated in a variety of clinical situations,
but its clinical relevance remains controversial (Lemaire).
In addition to its causal role in documented Gram-negative
sepsis and related syndromes, endotoxin has been associat-
ed, with varying degrees of supporting evidence, with
numerous other clinical syndromes. While some diseases,
such as meningococcal septicemia (meningococcemia)
(Brandtzaeg) and enteropathogenic
E. coli
syndromes
(Kaplan), involve documented infection by exogenous
Gram-negative bacteria, other conditions do not. For exam-
ple, blunt trauma (Brathwaite, Hiki, Langkamp-Henken,
Reed), burns (Jones II [a], Jones II [b]) and cardiac
(Anderson, Casey, Martinez-Pellus, Riddington, Rocke,
Taggart) or vascular (Baigrie, Roumen and Frieling)
surgery have all been associated with endotoxemia and sep-
sis, presumptively attributed to translocation of bacteria or
endotoxin from the gut.
There is abundant evidence that in the circulation, endotox-
in on or released from bacteria activates a systemic inflam-
matory reaction, a complex of cellular and humoral
responses in the host (Bone, Glauser, Rietschel, Remick).
Endotoxin stimulates reactions such as the release of
cytokines and arachidonic acid from monocytes, neu-
trophils, and vascular endothelial cells. Activated humoral
(non-cellular) pathways include the complement and coag-
ulation cascades. These responses of the normal compo-
nents of the host-defense system reflect the host's best
effort to battle a systemic infection without antibiotics to
reduce the bacterial load. However, if continually stimulat-
ed by the pathologic presence of endotoxin (as in an ongo-
ing infection or intestinal translocation), the prolonged
inflammatory response may damage or kill the host.
Because of the increasing incidence and lack of new treat-
ments for sepsis and related syndromes, as well as a grow-
ing appreciation for the protean manifestations of
endotoxin-related diseases, the medical community is tak-
ing renewed interest in the clinical significance of endotox-
Introduction
Page 7
2
in and endotoxemia. In the past decade, new research has
contributed to a growing understanding of the mechanisms
underlying these illnesses. This article reviews the molecu-
lar biology and pathophysiological mechanisms of endotox-
emia, sepsis, septic shock, and other diseases and
complications associated with endotoxin. The article also
presents some information about current and potential
future treatments of endotoxin-related disease.
B. Terminology and Approach
Conflicting terminology and confusing semantics have long
impaired communication in this field. The problem has
become more acute as clinical trials multiply and investiga-
tors, reviewers and regulators need a common language to
aid design, analysis and evaluation of trials. A 1992
American College of Chest Physicians (ACCP) Consensus
Conference report developed a conceptual framework and a
limited set of definitions in an attempt to standardize termi-
nology and facilitate communication.
These definitions, however, still depend on clinical diag-
noses based on signs and symptoms. There is at present no
laboratory or other test to determine cause (other than iden-
tifying particular infectious agents) and prognosis in sepsis
patients. Furthermore, the ACCP definitions do not encom-
pass milder or localized manifestations of exposure to
endotoxin, endotoxemia or the inflammatory response.
Because of the long-standing confusion of terminology in
this area, this paper uses a consistent common lexicon
throughout. The accompanying Glossary (see page 21)
defines terms central to the concepts presented here, as
well as those that have the greatest potential for ambiguity
or misinterpretation. While some of these terms have been
defined in the literature, many have not, and suffer multiple
and sometimes conflicting connotations from paper to
paper. We have used the ACCP definitions when possible
and have tried to be consistent with their conceptual frame-
work in defining other terms.
Because language drives perception, we have constructed
the Glossary with the intent of focusing the terminology on
two central themes of this article. First, sepsis (and there-
fore septic shock) are not diseases in their own right, but
clinical syndromes which complicate the course of patients
with pre-existing illnesses. Second, the systemic effects of
bacterial endotoxin exposure lie on a continuum from
asymptomatic Gram-negative bacteremia and endotoxemia
to a systemic inflammatory response syndrome (SIRS) that
may progress to sepsis and the multiple organ dysfunction
syndrome (MODS), through septic shock, organ failure and
death (Rangel-Frausto) (see Figure 1, inside front cover).
Inherent in this continuum model is an additional key con-
cept: there is a point in the progression where irreversible
clinical effects occur. Therefore, future specific therapies
should be aimed at aborting the progression of events
before this point of no return. There is some evidence to
suggest that intervention with an endotoxin-neutralizing
therapy can reverse the course of events even in septic
shock patients (Giroir). In general, however, early interven-
tion is better than late and interventions aimed at bacteria
and endotoxin should have more effect than those targeting
individual components of the sepsis cascade.
II. Basic Biology of Endotoxin
A. General Features
Bacterial endotoxins were first described at the end of the
last century after the recognition that, in addition to then-
known secreted toxins (exotoxins), certain types of bacteria
also produce biologically active, heat-stable molecules
associated with the bacterial cell itself (Rietschel). Initially
found in
Vibrio, Salmonella
, and
Serratia
species, endotox-
ins are now known to be a component of the outer mem-
brane of all Gram-negative bacteria (Carcillo, Glauser,
Rietschel, Remick, Ulevitch).
Purified endotoxin is a complex glycolipid composed of a
biologically active lipid (lipid A) linked to a polysaccharide
region (Glauser, Rietschel, Ulevitch). In addition to LPS,
other endotoxic cell membrane molecules have been identi-
fied, including lipooligosaccharide (LOS, a short-chain
endotoxin) and certain lipoproteins.
As depicted schematically in Figure 2 (opposite), the basic
endotoxin molecular structure consists of two distinct
regions: a hydrophilic carbohydrate (polysaccharide) por-
tion which includes an O-specific side chain and an inner
and outer core region, and the hydrophobic toxic lipid A
component (Glauser, Rietschel). Although the general
Basic Biology of Endotoxin
Page 8
3
structure is highly conserved among Gram-negative bacte-
ria, there is considerable structural variability at the O-spe-
cific chain between bacterial species.
Since the O-specific chain is enzymatically constructed by
the sequential addition of oligosaccharides, the endotoxin
of a given bacterium at a given point in time is a heteroge-
neous mixture of molecules with short, intermediate, and
long O-specific chains. Thus, there is no precise or stan-
dard way to measure molecular composition or molecular
weight of endotoxin. Evolutionary pressure exerted by
phagocytic cells and macrophages on Gram-negative bacte-
ria may account for some of this heterogeneity (Nikaido),
since the O-specific chain confers resistance to phagocyto-
sis and bactericidal agents such as complement (Rietschel).
Structural variation in the O-specific side chains produces
two distinct morphological types of Gram-negative bacteri-
al growth in culture, the "rough" (or short O-specific chain-
containing LPS) and the "smooth" (long chain-containing
LPS) variants. This variation is more than a microbiologi-
cal curiosity because of its impact on the disease-causing
potential of the organism. In laboratory and in animal
experiments, the smooth phenotype emerges as an impor-
tant virulence factor, conferring resistance to complement
mediated serum killing of bacteria (McCallum). Smooth
Salmonella
strains demonstrate accelerated rates of prolif-
eration and mortality in mouse models of infection
(Lyman). There also appear to be crucial human therapeu-
tic implications of the smooth/rough dichotomy, in that
anti-endotoxin antibodies have shown much lower binding
to smooth Gram-negative bacteria than to rough strains
(Siegel).
The lipid A component of endotoxin is highly conserved
from one Gram-negative bacterial family to another and
gives the endotoxin molecule its toxicity (Rietschel),
whether as a component of a viable microorganism or
when shed from the cell wall. The most powerful evidence
implicating lipid A as the biologically-active portion of
endotoxin involves studies using synthetic molecules.
These show that lipid A, independent from all carbohydrate
constituents, is as toxic as its naturally-occurring endotoxin
counterpart (Ulevitch). The actual endotoxic activity of
LPS is believed to be dependent upon the specific confor-
mation of the lipid A portion of the molecule. At high
concentrations this conformation appears to be a three-
dimensional nonlamellar structure (Schromm). It is
Basic Biology of Endotoxin
Repeating
Unit
Outer Core
Inner Core
O-Specific Chain
Core
Lipid A
Adapted from Rietschel,
et al., Progress in Clinical
& Biological Research
189:31-51, 1985
Polysaccharide
Figure 2: Bacterial Lipopolysaccharide (LPS)
Page 9
4
believed that this conformation enables endotoxin to maxi-
mally interact with specific humoral and cellular host fac-
tors, triggering the inflammatory cascade.
B. Circulating Endotoxin (Endotoxemia)
In blood or serum, Gram-negative bacteria may release
endotoxin in a variety of forms, such as membrane frag-
ments, blebs, and vesicles, in combination with bacterial
phospholipids (Parker). Once in the circulation, LPS may
be bound by a large number of serum constituents, some of
which enhance its pathogenicity while others act to neutral-
ize its effects. In the former category are LBP and soluble
CD14 (Ulevitch), which are discussed in a subsequent sec-
tion (see "Activation of Cellular Mediators", page 5).
Among the best-described natural binding ligands for LPS
is bactericidal/permeability-increasing protein (BPI), a
polypeptide found in neutrophil azurophilic granules
(Elsbach & Weiss). Besides having bactericidal activity, (as
its name implies), BPI binds with high affinity to LPS and
neutralizes it as well as facilitating its clearance from the
circulation. BPI and LBP are closely related, and show
more distant sequence homology to two lipid transport
proteins, cholesterol ester transfer protein (CETP) and
phospholipid transfer protein (PLTP), suggesting common
mechanisms of lipid binding in all proteins (Beamer).
Interestingly, LPS is also bound by other normally circulat-
ing lipoproteins, including high-density, low-density, and
very-low density lipoproteins and chylomicrons (Parker).
III. Pathophysiology of the Endotoxin-
Induced Inflammatory Response
A. Routes of Exposure to Endotoxin
Humans may be exposed to endotoxin via two routes. The
first and most widely appreciated is systemic or localized
Gram-negative bacterial infection of exogenous source. As
a consequence of infection by a specific pathogen, bacteria
and bacterial cell wall fragments can cause local or sys-
temic inflammatory responses. Current therapeutic efforts
are primarily directed against the underlying infection-
viz., antibiotics. However, even when the bacteria are suc-
cessfully killed, their residual endotoxin can continue to
fuel an inflammatory response.
It has been put forward that antibiotic treatment of Gram-
negative bacterial infections may, ironically, increase endo-
toxin load and exacerbate the inflammatory response
(Prins). Some animal and human studies suggest that
antibiotic-induced bacteriolysis liberates LPS (Jackson,
Prins, Shenep). Antibiotic classes may vary in this respect;
one study in surgical intensive care patients found that cef-
triaxone and cefotaxime were associated with greater endo-
toxin levels than were tobramycin, vancomycin,
ciprofloxacin, and imipenem (Holzheimer). But other stud-
ies have found no significant difference between imipenem
and ceftriaxone (Prins). Antibiotic-associated endotoxin
release remains unproven and its clinical significance is
unknown. Nevertheless, further research may lead to new
approaches to patient management, such as more selective
antibiotic choices (Prins) and synergistic use of endotoxin
binding and neutralizing agents in conjunction with antibi-
otics (Elsbach & Weiss).
The second, less well-recognized route of endotoxin expo-
sure is bacterial translocation from the gut (Lemaire, van
Leeuwen). The gastrointestinal tract normally contains a
population of nonpathogenic bacterial flora, primarily
Gram-negative anaerobes. Outer-membrane fragments of
Gram-negative bacteria, including endotoxin, are continu-
ously produced within the normal gut, without apparent
harm to the host (van Leeuwen). In fact, there is consider-
able evidence showing that minute amounts of endotoxin
are constantly being shed into the portal circulation by the
healthy gut and cleared by cells in the liver (Jacob,
Mathison, Nolan, Ruitter). During this process, LPS is nor-
mally taken up by endothelial and Kupffer cells, and possi-
bly hepatocytes, via pinocytotic or receptor-dependent
mechanisms (van Leeuwen), and is thereby rendered harm-
less to the host before reaching the systemic circulation.
Pathologic translocation may lead to endotoxin-related ill-
ness when one or more of the natural host controls of this
process fails, allowing excessive quantities of bacteria or
endotoxin to exit the gut via lymphatic or vascular channels
(Deitch, van Deventer, van Leeuwen). When this occurs,
high concentrations of endotoxin can be found in the
mesenteric lymph nodes, liver, spleen and general circula-
tion. While the precise methods by which endotoxin can
overwhelm physiologic host barriers are unknown, two
Pathophysiology
Page 10
5
mechanisms have received the most attention: breakdown
in gut mucosal integrity that allows bacteria and endotoxin
to "flood" the bloodstream, and/or impairment of the liver's
normal clearance mechanisms. With respect to the first
hypothesis, numerous investigators have postulated that a
variety of insults that impair normal blood flow and lead to
varying degrees of gut ischemia can compromise the
integrity of the gut mucosal barrier and allow "leakage" of
endogenous LPS (Antonsson, Baigrie, Brewster, Casey,
Martinez-Pellus, Riddington, Roumen & Freiling). This
general mechanism has been invoked to explain the occur-
rence of SIRS or sepsis in many clinical situations where a
primary site of infection may not be obvious (e.g., trauma
or burns, as discussed in detail below).
The second mechanism by which translocated endotoxin
can lead to SIRS or sepsis is hypothesized to be impaired
liver clearance of LPS. This concept is documented in liter-
ature which shows that elevated circulating endotoxin lev-
els occur in patients with cirrhosis, alcoholic liver disease
and other conditions that result in hepatic failure (Bode,
Fukui, Schafer). More specifically, these high LPS levels in
the blood and lymphatic system have been attributed to
decreased clearance of LPS from the portal circulation
caused by intra-hepatic vascular shunts (which allow the
LPS to circumvent the liver entirely), endothelial dysfunc-
tion, and the Kupffer cell/reticuloendothelial system (RES)
impairment which is known to occur in chronic liver dis-
ease. The extent to which these elevated LPS concentra-
tions promote systemic illness is unclear, but at least one
investigator has suggested that they may contribute to the
occurrence of hepatic encephalopathy (Odeh), perhaps
explaining the reported beneficial effects of non-absorbable
antibiotics in this syndrome.
While clinical sources and abundant animal data demon-
strate that both increased gut permeability and translocation
of endotoxin occur in association with a variety of systemic
insults (van Deventer), data demonstrating that translocated
LPS is directly pathogenic in humans are scant (Lemaire).
Nevertheless, continued interest in bacterial translocation
as a source of disease is fueled by the well-recognized
occurrence of SIRS and shock in patients without culture-
positive bacteremia or other clinically apparent sources of
infection but with morbidity and mortality rates equivalent
to those of culture-positive sepsis and septic shock patients
(Rangel-Frausto). Clinical settings in which this occurs
include immunosuppression, starvation, thermal and radia-
tion injuries, hemorrhagic shock, blunt trauma, chemother-
apy, and cardiac and vascular surgical procedures. These
conditions have all been associated with gut ischemia
and/or impaired RES function and may therefore predis-
pose to bacterial/ endotoxin translocation, which may result
in endotoxemia and sepsis (Brathwaite, Saadia, van
Leeuwen).
B. Host Interactions with Endotoxin
Endotoxin exerts its highly complex array of pathophysio-
logic effects by interacting in the host with a panoply of
naturally-occurring cellular and humoral elements (Bone,
Glauser, Rietschel, Remick, Ulevitch); see Figure 3 [inside
back cover]. These elements routinely mediate the normal
host response against infectious insults. In SIRS or sepsis,
however, the host's normal homeostatic mechanisms break
down and the inflammatory response manifests as fever,
vascular leakage, myocardial depression and shock
(Rietschel, Suffredeni).
1. Activation of cellular mediators-LBP and CD14
Endotoxin interacts with virtually all components of the
cellular immune system. It is taken up by neutrophils, lead-
ing to cell activation and the subsequent enhancement of
the phagocytic ability of these cells. Further, it may activate
neutrophils to express cell adhesion molecules which medi-
ate neutrophil-to-neutrophil, neutrophil-to-vascular
endothelial cell and neutrophil-to-tissue binding, causing
local inflammation and vascular leakage (Glauser,
Rietschel). LPS also appears to affect various populations
of lymphocytes, stimulating B-cell proliferation and anti-
body production, activating T-cells to secrete cytokines,
and down-regulating T-suppressor cells (Rietschel).
The most widely studied and probably the most significant
cellular effects of endotoxin involve the interaction with
cells of the monocyte/macrophage lineage (Glauser,
Rietschel, Remick), which express a membrane receptor
known as CD14 (Remick). Circulating LPS is bound by a
glycoprotein serum factor, LBP, which facilitates binding
of LPS to its principal cellular receptor, the CD14 molecule
(Ulevitch). The importance of this interaction is demon-
Pathophysiology
Page 11
6
strated by experiments in which preventing LPS-LBP bind-
ing to monocytes blocks the activity of endotoxin
(Remick). Binding of LPS-LBP to CD14 induces mono-
cytes to produce and secrete a myriad of pro- and anti-
inflammatory cytokines, including interleukins (IL-1, IL-6,
IL-8, IL-10), macrophage migration-inhibitory factor, and
tumor necrosis factor (TNF) (Rietschel, Remick, Ulevitch).
While numerous other humoral mediators are induced by
LPS (see below), the overwhelming systemic production of
the inflammatory cytokines appears to be a central compo-
nent of the life-threatening organ failure and shock that
characterizes endotoxin-related SIRS and sepsis (Rietschel,
Remick).
2. Role of cytokines in SIRS and sepsis
The cytokines TNF, IL-1, IL-6 and IL-8, when expressed in
limited quantities and confined to a local area, play a bene-
ficial role in stimulating the host defense system to destroy
invading microorganisms (Mastroeni). Yet, in endotoxemia,
they are released systemically and in that setting may
become crucial mediators accelerating the progression to
SIRS and sepsis (Bone, Froon, Glauser, Gardlund,
Rietschel). (See Figure 3, inside back cover.)
This sometimes sinister role of cytokines in sepsis is
supported by several lines of evidence, among which are:
injections of TNF and IL-1 into animals induce physiologi-
cal responses that are similar to those of patients with septic
shock (Remick); inhibition of TNF and IL-1 prevents organ
damage and death in animals with septic shock (Opal,
Rydberg); and plasma levels of TNF in certain sepsis
patients have sometimes been shown to correlate with prog-
nosis (Brandtzaeg, Gardlund, Roumen & Hendriks).
Moreover, TNF, IL-1 and IL-6 stimulate receptor-carrying
cells, resulting in the intensification of the host response to
circulating LPS (Rietschel). When so activated, monocytes
and macrophages are induced to release biologically-active
molecules such as platelet activating factor, leukotrienes,
prostaglandins, oxygen radicals, and pro-inflammatory pro-
teases (e.g., elastase and collagenase), the primary media-
tors of the tissue damage characteristic of a systemic
inflammatory response (Bone). In addition, cytokine over-
stimulation, endothelial dysfunction and damage caused by
nitric oxide release, leukocyte adherence to vessel walls and
consumptive coagulopathy (discussed below) lead to
vasodilatation, vascular leakage and refractory hypotension.
Many of these humoral mediators act as endogenous pyro-
gens, causing fever. They also stimulate the release of
ACTH, cortisol, and macrophage migration inhibitory fac-
tor and induce the liver to produce acute-phase proteins
(Baumann, Steel), such as LBP (described above)
(Glauser). Circulating TNF, in conjunction with the cyto-
modulators produced by activation of the complement sys-
tem (discussed below), causes leukocytes to adhere to
endothelial cells, resulting in leukopenia, and blood vessel
and capillary injury (Rietschel).
3. Activation of other humoral mediators
Gram-negative bacteria activate the complement system
through two separate pathways: bacteria and bacterial cell
wall components complexed with antibodies activate the
classical (antibody-dependent) complement pathway
intended to kill the bacteria, while the bacteria and endo-
toxin directly activate the alternative (non-antibody) path-
way (Glauser). The resulting complement cascade induced
by LPS produces, among other mediators, the anaphylotox-
ins C3a and C5a, which contribute to vasodilatation,
increased vascular permeability, and circulatory collapse.
In addition, complement components induce adhesion and
activation of platelets and neutrophils, stimulating the sec-
ondary events of platelet aggregation, release of lysosomal
enzymes and arachidonic acid metabolites, and microvas-
cular injury. The damage from inappropriate (pathologic)
complement consumption is interlinked with overproduc-
tion of cytokines.
The precise role of arachidonic acid pathway mediators in
sepsis and related syndromes is still under investigation.
LPS-induced activation of susceptible cells, such as neu-
trophils, leads to the release of prostaglandins,
leukotrienes, and other agents with vasoactive and pro-
inflammatory effects. Presently, the extent to which these
well-known molecules contribute to shock, or provide
therapeutic targets in the treatment of endotoxin-induced
syndromes, remains to be elucidated.
Endotoxin is the most potent known exogenous activator
of the coagulation system. As with its effects on comple-
Pathophysiology
Page 12
7
ment and cytokines, endotoxin converts the normally bene-
ficial coagulation system into a pathological cascade.
Factor XII (Hageman factor) of the coagulation cascade
plays an important role in the pathogenesis of shock. When
activated by LPS or lipid A, Factor XII triggers the intrin-
sic coagulation pathway by activating Factor XI and by
stimulating endothelial cells and macrophages to produce
tissue factor. The process of activating the intrinsic coagu-
lation pathway also activates the extrinsic coagulation path-
way, and both participate in the development of
disseminated intravascular coagulation (DIC) (Glauser).
Tissue factor, readily induced by endotoxin, may be
responsible for stimulating DIC, since antibodies to tissue
factor can prevent this in rabbits given endotoxin (Warr).
LPS-activated Factor XII also contributes to hypotension
and shock by converting prekallikrein into kallikrein,
which in turn cleaves kininogen to release the potent
hypotensive agent bradykinin (Colman).
The host response to LPS also includes the production and
release of the potent vasodilator nitric oxide. Nitric oxide is
a vascular relaxing agent produced by macrophages and
endothelial cells (Palmer). When released, it induces
vasodilation which, when extensive, results in hypotension.
LPS-induced nitric oxide release by macrophages takes up
to several hours, whereas its release by endothelial cells
takes only a few minutes. Although the role of nitric oxide
(NO) in the acute inflammatory cascade is still being inves-
tigated, its rapid release by endothelial cells may be the
cause of the precipitous drop in blood pressure associated
with septic shock (Vane). However, clinical trials of NO
inhibitors have not shown a survival benefit.
The role of endogenous opioids in septic shock is poorly
understood. The concept that endorphins may contribute to
shock stems from two findings: opioid peptide secretions
can be induced by endotoxin; and the opioid antagonist,
naloxone, has some activity in reversing endotoxin-induced
hypotension (Hackshaw), but has shown no survival benefit
in the clinic. More research is needed to elucidate what
role, if any, endorphins have in the development of sepsis.
C. Summary:
Pathogenesis of the Inflammatory Cascade
A multifaceted host response can be triggered by endotox-
in. Possible sources of endotoxin include exogenous Gram-
negative bacterial exposure or gut translocation and failure
of hepatic uptake and clearance mechanisms. Uncleared
endotoxin not neutralized by naturally-occurring cellular
components such as BPI in polymorphonuclear leukocytes
(PMNs) will interact with LBP. The LBP/LPS complex,
which binds selectively to soluble and membrane-bound
CD14, is the primary trigger of the production and release
of crucial humoral mediators (TNF, interleukins) by mono-
cytes/macrophages, endothelial cells, granulocytes and
lymphocytes. As outlined above, when homeostatic mecha-
nisms break down, the interconnected cellular and humoral
inflammatory cascades can lead to shock and organ failure.
As is easily discernible from Figure 3 (inside back cover),
this process is enormously complex and involves multiple
simultaneous and self-propagating cascades.
For example, TNF, IL-1 and IL-6 induce fever and cause
the liver to release acute phase proteins which may lead to
the release of additional TNF (Baumann, Geller, Glauser,
Steel). Blood clotting factors are consumed and the com-
plement system is activated to produce additional cytomod-
ulators which, in conjunction with TNF and leukocyte
aggregation, can lead to leukopenia, blood vessel injury
and capillary leakage. Endothelial cells are stimulated to
produce nitric oxide, which causes vasodilation, hypoten-
sion and increased cardiac output. T cells release colony-
stimulating factor and interferon
, causing leukocytosis
and stimulating macrophages to produce humoral mediators
and further perpetuate the inflammatory response (Glauser,
Rietschel).
If the normal host response spins out of control, the result-
ing catastrophic clinical illness, known as sepsis when
associated with an identified infectious process, (or as
SIRS, when no infectious agent is identified), is character-
ized by fever, chills, leukopenia or leukocytosis, and
hypotension despite tachycardia and marked increases in
cardiac output. The overwhelming systemic inflammation
may lead to DIC and hemorrhage, the vascular leakage
described above, and pulmonary edema progressing to the
acute respiratory distress syndrome (ARDS). Refractory
Pathophysiology
Page 13
8
hypotension ("septic shock" in the presence of infection)
progresses to life-threatening decreases in organ perfusion,
manifested as metabolic acidosis, renal insufficiency,
obtundation and coma, intestinal ischemia, and, ultimately,
terminal respiratory failure and/or cardiovascular collapse
(Glauser, Parillo, Rietschel).
Recent investigations have added a new dimension to the
picture of the sepsis cascade. A decade ago, sepsis was felt
to be a "horse-out-of-the-barn" phenomenon-in other
words, once endotoxin initiates events, the pathogenic cas-
cade is self-perpetuating and unstoppable. The current
view, however, posits that the continuous presence of endo-
toxin is necessary to maintain the SIRS in addition to sim-
ply initiating it (Dedrick, Huang). This concept brings a
strong note of optimism to newer therapeutic efforts
because it suggests that even late in the clinical course,
specific endotoxin-neutralization therapy may be able to
abort established but still-reversible SIRS, sepsis and septic
shock (Giroir).
D. Diagnostic and Prognostic Markers of SIRS
and Sepsis
Given the heterogeneous clinical presentations of sepsis
and septic shock, the difficulty in making a definitive diag-
nosis with currently available technology, and the urgency
of instituting potentially life-saving therapy, it is no wonder
that numerous attempts have been made at developing lab-
oratory techniques to detect endotoxemia. To date, howev-
er, there is no reproducible, validated laboratory test for
documenting endotoxemia; all attempts thus far have been
plagued by methodological problems, assay variability, and
lack of clinically useful specificity and sensitivity. As a
result, clinicians have neither a laboratory tool for making
an unequivocal diagnosis nor a prognostic marker to identi-
fy those patients who might benefit from specific therapeu-
tic interventions (Goldie).
Many attempts have been made to utilize serum endotoxin
assays as a diagnostic test. Although endotoxin has been
found in the circulation in about two thirds of septic
patients in several trials, there is as yet no consensus about
its utility as a clinical marker. While some groups have
reported a good correlation between whole blood endotoxin
levels and clinical course in sepsis and septic shock
patients (Danner, Ng), most other authors have been unable
to demonstrate either diagnostic or prognostic value of
blood endotoxin assays (Elin, Engervall, Goldie, Guidet,
Rintala, Stumacher). Thus, the practicality and usefulness
of measuring circulating endotoxin in the clinical setting
remain to be demonstrated.
There are numerous technical and biological issues which
hamper the development of clinically-useful endotoxin
diagnostic methods. Endotoxin release is episodic and cir-
culating LPS has a short half-life (minutes), obscuring the
value of a single determination. In the bloodstream, LPS is
distributed in varying proportions bound by LBP, micelles,
chylomicrons, and various other lipid fractions; some of
these bound moieties are biologically inactive, but most
assays measure all LPS whether biologically active or
not-again, making the relevance of the results uncertain.
Further, assays are measured against positive controls, yet,
as discussed earlier, each bacterial species has different
LPS composition, and the most appropriate control strain
has never been defined. Finally, false positive results can
lead to unwarranted and dangerous treatment while false
negative results could be catastrophic for the patient, par-
ticularly if effective anti-endotoxin therapy was available.
Additionally, all currently available LPS/endotoxin assays
are different, and results from one cannot be correlated to
results from another. Therefore, they share one paramount
clinical characteristic: all are unsuitable for use as diagnos-
tic, prognostic, or patient monitoring tools. These limita-
tions have contributed to the lack of regulatory approval for
such assays for diagnostic use in patients in all countries
other than Japan.
As the limitations of direct measurement of endotoxin lev-
els have become apparent, the search for other clinically
useful biological markers of exposure to endotoxin has
been extended to cytokines and other inflammatory modu-
lators-again, without notable success. Among the
cytokines evaluated are TNF, IL-1, IL-6, and IL-8, with
generally inconclusive results (Goldie, Rhodes). Early sug-
gestions that elevated IL-6 levels, when combined with
assays of endotoxin and/or phospholipase-A2, are useful in
the management of febrile, neutropenic cancer patients
await further confirmation (Engervall, Rintala), as does the
Pathophysiology
Page 14
9
observation that circulating IL-6 levels >3000 pg/mL pre-
dict mortality in intensive care patients (Goldie).
A variety of other naturally occurring serum proteins have
been advanced as candidates for the laboratory diagnosis of
SIRS and sepsis, but as yet none have been subjected to
rigorous field testing, independent validation, or clinical
confirmation. In a comprehensive study of 146 patients,
circulating endotoxin, TNF, IL-1
, and IL-6, and two forms
of soluble TNF receptor, IL-1 receptor antagonist, and anti-
endotoxin core antibodies were evaluated. The authors sug-
gested that low concentrations of IgG anti-core antibodies
correlated with mortality (Goldie). Phospholipase-A2, a
marker of neutrophil activation and a key enzyme in the
arachidonic acid inflammatory cascade, appeared to be a
sensitive marker of acute lung and other organ injury, and
perhaps sepsis (Rae, Rhodes). And although much recent
attention has been focused on the use of procalcitonin as a
marker of systemic inflammation and a predictor of out-
comes in septic shock, external confirmation is still needed
(de Warra, Meisner, Rhodes).
Because of its critical position early in the inflammatory
process, it has been suggested that LBP may be a better tar-
get than the cytokines for diagnostic and prognostic devel-
opment. LBP is a plasma protein produced in the liver in
response to endotoxin exposure. Plasma levels of LBP are
elevated in patients with diseases characterized by exposure
to Gram-negative bacteria and endotoxin, such as Gram-
negative sepsis, abdominal infections, meningococcemia,
Crohn's disease, and ulcerative colitis (Carroll). Cystic
fibrosis patients, who suffer recurring bouts of lung infec-
tions, usually by Gram-negative
Pseudomonas
bacteria,
also have elevated LBP levels. Furthermore, while plasma
LBP levels were low in hemorrhagic trauma and liver
surgery patients immediately after trauma or surgery,
sequential sampling showed that LBP levels become highly
elevated within several days of the original insult. This not
only provides support for bacterial translocation, but also
suggests that LBP itself may be a useful diagnostic and
prognostic marker across a range of septic and non-septic
complications.
Although this is beyond the scope of this review, there is
also an extensive literature evaluating a myriad of physio-
logic parameters as prognostic markers in sepsis and septic
shock. These have included blood pressure, vascular resis-
tance, cardiac index and other derived hemodynamic para-
meters, systemic oxygen delivery and tissue oxygen
consumption, anion gap, and gastric tonometry (Rhodes).
As with laboratory tests of LPS and other chemical mark-
ers, there is as yet no consensus about the utility or speci-
ficity of any of these measures for diagnosing sepsis or
SIRS, predicting outcomes, or guiding therapeutic deci-
sions. Research continues in the hope of identifying indi-
vidual or combination markers that can improve treatment
strategies and, thereby, prognosis (Rhodes).
IV. Endotoxin-Related Clinical
Syndromes
Sections IV and V will review the clinical consequences of
endotoxin exposure. Section IV starts with definitions of
sepsis, SIRS and associated severe organ dysfunction syn-
dromes and ends with a discussion of meningococcemia, a
unique Gram-negative bacteremic syndrome. This is fol-
lowed by a summary of syndromes that may be associated
with gut translocation of Gram-negative bacteria and/or
LPS. Finally, Section V presents a series of more localized
illnesses whose pathogenesis may, in part, be related to
LPS. (These illnesses are summarized in Table 1, pp 12-13.)
A. Sepsis, Septic Shock and SIRS
Conflicting terminology and confusing semantics have long
impaired communication in the field of sepsis. The 1992
ACCP Consensus Conference report developed definitions,
built upon a body of previous epidemiological and clinical
observations (Bone & Balk, Rangel-Frausto) in an attempt
to standardize terminology and facilitate communication.
Resolving these issues is particularly important as clinical
trial activity grows and clinical investigators, reviewers,
and regulatory authorities require a common language for
assessing clinical presentations, trial entry criteria, subpop-
ulation analysis and outcome measures. At the same time,
the ACCP's definitions point out that the diagnosis of
SIRS, sepsis and septic shock remain based upon a charac-
teristic constellation of clinical signs and symptoms. There
is, at present, no single diagnostic criterion that establishes
the presence of SIRS, sepsis or septic shock.
Clinical Syndromes
Page 15
10
The ACCP introduced the term "systemic inflammatory
response syndrome" (SIRS) to describe the general sys-
temic inflammatory process independent of cause. It is
symptomatically characterized by hyper- or hypothermia,
tachycardia, hypoventilation and/or leukocytosis. The term
"sepsis" is now defined as the "systemic inflammatory
response to infection," that is, SIRS plus a culture-docu-
mented infection. "Septic shock" is considered a subset of
sepsis (and therefore requires a documented infection) and
is defined as "sepsis-induced hypotension, persisting
despite adequate fluid resuscitation, along with the pres-
ence of hypoperfusion abnormalities or organ dysfunction"
(ACCP). (See Figure 4 above)
More specifically, the diagnosis of sepsis is defined by the
ACCP as a systemic response to a culture-documented
infection consisting of two of the following four criteria:
* Temperature > 38°C or < 36°C
* Heart rate > 90 beats/minute
* Respiratory rate >20 breaths/minute or a PaCO
2
< 32 torr
* White blood cell count >12,000 cells/mm
3
,
< 4000 cells/mm
3
, or > 10% immature forms.
Patients who demonstrate identical clinical findings but
who do not have a detectable infection are classified as
having SIRS.
Septic shock
represents an extreme manifestation of the
sepsis syndrome, and includes patients meeting the above-
Infection
Sepsis
SIRS
Bacteremia
Fungemia
Parasitemia
Viremia
Other
Other
Trauma
Burns
Pancreatitis
Roger C. Bone and the ACCP/CCCM Consensus
Conference Committee, Chest, 101:6,1644-1655.
Blood-Borne Infection
Figure 4: An Earlier Proposed Interrelationship Between Systemic
Inflammatory Response Syndrome (SIRS), Sepsis, and Infection
Clinical Syndromes
Page 16
11
mentioned criteria (including the presence of documented
infection) who also demonstrate refractory (in the absence
of medical intervention) arterial hypotension and clinical
manifestations of hypoperfusion, such as lactic acidosis,
oliguria, or acutely depressed mental status.
SIRS (no detected infection) with shock should therefore
be referred to as "SIRS plus shock", "shock of unknown
origin" or "suspected or presumed septic shock", but com-
mon usage is still not consistent in this regard. The absence
of a documented infective source does not necessarily elim-
inate the possibility of exposure to infectious agents includ-
ing Gram-negative bacteria translocated from the gut.
As it progresses, the end stages of septic or SIRS-related
shock may include other clinical syndromes distinct enough
to warrant specific names, such as the various organ dys-
functions: acute renal failure (ARF), acute respiratory dis-
tress syndrome (ARDS), hepatobiliary dysfunction (HBD),
central nervous system dysfunction (CNSD), or disseminat-
ed intravascular coagulation (DIC). The presence of more
than one of these organ dysfunctions comprises multiple
organ dysfunction syndrome (MODS). Like septic shock,
this syndrome is associated with poor prognosis and with
increased mortality rates (ACCP). The ACCP did not
specifically define the organ dysfunctions (i.e, ARF, ARDS,
HBD, CSND and DIC) associated with SIRS. However,
they recommended using the term "multiple organ dysfunc-
tion syndrome (MODS)", defined as refractory inability to
maintain organ homeostasis in the absence of medical
intervention. This would replace the dichotomous term
"organ failure" with a continuum of functional derange-
ments.
ARDS refers generically to the most severe form of acute
lung injury, characterized by diffuse pulmonary inflamma-
tion, increased lung capillary permeability, pulmonary
edema and respiratory insufficiency (Lamy). Primary
ARDS is caused by direct lung injury (for example, drown-
ing or toxic inhalation); secondary ARDS occurs common-
ly through indirect, systemic mechanisms such as those that
characterize septic shock. As a late stage complication of
septic shock, ARDS may occur alone, or as the pulmonary
component of MODS. Studies of trauma patients reveal
that the lungs are the first organ system to fail in the pres-
ence of endotoxin (Welbourne), and many investigators feel
that understanding and preventing the effects of endotoxin
on the lung may be crucial to preventing the failure of
additional organs.
When multiple organs (such as the heart, lungs, and kid-
neys) become dysfunctional-as defined by the inability to
maintain normal homeostasis in the absence of medical
intervention-the resulting clinical picture is termed
MODS (ACCP). MODS was recently clarified and defined
by the ACCP according to the circumstances surrounding
its onset. Primary MODS occurs in response to a direct
insult to an organ and includes such events as pulmonary
contusion or coagulopathy due to multiple transfusions
(ACCP). On the other hand, secondary MODS is a conse-
quence of an abnormal and overwhelming host inflammato-
ry response. Secondary MODS occurs with some latency
after the acute insult, involves distant organs in the sys-
temic inflammatory response, and is most frequently
observed as a complication of severe infection (ACCP). In
the context of sepsis, MODS is typically characterized by
pulmonary and/or renal failure, circulatory failure, and
hepatic, gastrointestinal and central nervous system dys-
function. Organ failure, like septic shock, is diagnosed
using clinical criteria; the definitions of any of these organ
dysfunctions are not universally agreed upon.
Sepsis and septic shock are not syndromes that develop in
healthy persons; rather, they occur in patients already suf-
fering acute catastrophic illness, severe underlying disease,
or major trauma (Bone). Likewise, patients at greatest risk
of dying are those with pre-existing physiologic compro-
mise, such as advanced age, malignancy, immunosup-
pressed status, or major organ dysfunction. It has been
postulated that these conditions predispose to sepsis and
mortality because they independently induce the release of
the same pro-inflammatory activators that mediate septic
shock (Bone).
B. Meningococcemia
Neisseria meningitidis
is a Gram-negative organism
(meningococcus) whose natural habitat is the human
nasopharynx. It is most commonly associated with epidem-
ic or sporadic meningitis in children and young adults. The
cell wall in
N. meningitidis
bacteria incorporates an endo-
toxin (lipooligosaccharide, LOS) that may be responsible
Clinical Syndromes
Page 17
12
Clinical Conditions
Clinical Condition
US Incidence
Possible Mechanisms of Endotoxin Exposure
Sepsis/septic shock
500,000 cases/yr
1
(hospitalized)
various identified infectious agents: bacteria, fungi
SIRS
unknown
no documented infectious source
Meningococcemia
< 3000 cases/yr
2
Neisseria meningitidis
bacteremia
Trauma/hemorrhagic shock
> 250,000 cases/yr * < 40% complications
intestinal translocation related to blood loss
Burn injuries
50,000 cases/yr
1
(hospitalized)
infection and/or translocation
Cardiovascular surgery
600,000 surgeries/yr
3
intestinal translocation associated with ischemia
(Cardiopulmonary bypass; aneurism repair)
Liver surgery/ transplant
< 4000 transplants/yr
4
* < 50% complications
gut translocation plus impaired liver clearance of LPS
Liver disease (hepatitis B & C, cirrhosis etc.)
> 4,000,000 chronic cases/yr
4
* 26,000 deaths/yr
impaired liver clearance of LPS
Acute pancreatitis
80,000 cases/yr
5
similar to post-trauma and -surgical sepsis
Inflammatory Bowel Disease
1-2 million cases/yr
5
gross impairment of gut integrity may lead to translocation
Necrotizing Enterocolitis
2000-4000 cases/yr
11
* 1000 neonate deaths
focal or systemic infection, gut translocation
Periodontal disease
7.5 million/yr
7
treated for ~ 50 million affected
LPS from infecting bacteria
Pneumonia
1.2 million in hospital/yr * 82,000 deaths/yr
2
exogenous infection/shock-related translocation
Lung infections in Cystic Fibrosis patients
30,000 people with CF
6
colonization by Gram-negative bacteria
Asthma
14.5 million new cases/yr
2
LPS-containing allergenic dusts that trigger
inflammatory response
Coronary Artery Disease
1.1 million heart attacks/yr
3
* 481,000 deaths/yr
3
infection and/or translocation
Congestive Heart Failure
400,000 new cases/yr * 43,000 deaths/yr
3
translocation due to hypoperfusion
Complications of renal dialysis
181,000 renal dialysis patients
5
nosocomial infections
Hemolytic Uremic Syndrome (
E. coli
O157:H7)
27,000 cases
8
disruption of GI tract by infection by exotoxic enteropathogen
Autoimmune diseases
500,000 rheumatoid arthritis/yr
9
LPS induction of inappropriate immune response
Cancer
575,000 in chemotherapy/yr
10
chemotherapy-induced translocation and neutropenia
1. National Center for Health Statistics, Bethesda, MD
2. Centers for Disease Control (CDC)
3. American Heart Association
4. American Liver Foundation
5. National Institute of Diabetes and Digestive and Kidney
Diseases (NIH)
6. Cystic Fibrosis Foundation
7. American Dental Association
Page 18
13
Clinical Conditions
US Incidence
Possible Mechanisms of Endotoxin Exposure
Comments
500,000 cases/yr
1
(hospitalized)
various identified infectious agents: bacteria, fungi
many predisposing conditions; elevated LPS & LBP
unknown
no documented infectious source
inability to culture organism does not rule out infection
< 3000 cases/yr
2
Neisseria meningitidis
bacteremia
classic example of fulminant sepsis; elevated LPS & LBP
> 250,000 cases/yr * < 40% complications
intestinal translocation related to blood loss
elevated LBP, LPS levels variable
50,000 cases/yr
1
(hospitalized)
infection and/or translocation
sepsis is a frequent complication
600,000 surgeries/yr
3
intestinal translocation associated with ischemia
infectious complications frequent
< 4000 transplants/yr
4
* < 50% complications
gut translocation plus impaired liver clearance of LPS
complications include pneumonia and sepsis
> 4,000,000 chronic cases/yr
4
* 26,000 deaths/yr
impaired liver clearance of LPS
may lead to endotoxemia
80,000 cases/yr
5
similar to post-trauma and -surgical sepsis
elevated LPS
1-2 million cases/yr
5
gross impairment of gut integrity may lead to translocation
exacerbations often complicated by SIRS/sepsis;
elevated LBP, variable LPS
2000-4000 cases/yr
11
* 1000 neonate deaths
focal or systemic infection, gut translocation
elevated LPS, cytokines
7.5 million/yr
7
treated for ~ 50 million affected
LPS from infecting bacteria
clinical significance unknown
1.2 million in hospital/yr * 82,000 deaths/yr
2
exogenous infection/shock-related translocation
like sepsis, a frequent complication of trauma, surgery
30,000 people with CF
6
colonization by Gram-negative bacteria
elevated LBP, CF predisposes to recurring infection
14.5 million new cases/yr
2
LPS-containing allergenic dusts that trigger
inflammatory response
1.1 million heart attacks/yr
3
* 481,000 deaths/yr
3
infection and/or translocation
controversial
400,000 new cases/yr * 43,000 deaths/yr
3
translocation due to hypoperfusion
181,000 renal dialysis patients
5
nosocomial infections
27,000 cases
8
disruption of GI tract by infection by exotoxic enteropathogens
500,000 rheumatoid arthritis/yr
9
LPS induction of inappropriate immune response
575,000 in chemotherapy/yr
10
chemotherapy-induced translocation and neutropenia
elevated LPS, septic complications
8. Healthway Online (www.healthanswers.com)
9. CIBC Oppenheimer figures for Rheumatoid Arthritis
(~ 1/2 of all cases of autoimmune disease)
10. Medical and Healthcare Marketplace Guide, 1998
11. National Institute of Child Health and Human Development
Page 19
14
for some of the nervous system tissue damage that occurs
during meningitis.
In some patients, the primary manifestation of meningococ-
cal infection is meningococcal septicemia or meningococ-
cemia, a characteristic acute systemic inflammatory
syndrome marked by meningococcal bacteremia, septic
shock, and high mortality (Brandtzaeg). Meningococcemia
is a unique and well-characterized example of Gram-nega-
tive bacteremia, and can be viewed as a particularly fulmi-
nant form of Gram-negative sepsis.
Unlike most episodes of septic shock, where an underlying
medical problem predisposes the patient to infection and
sepsis, meningococcemia unexpectedly strikes previously
healthy children and young adults. The illness is character-
ized by rapid onset; patients may progress from undifferen-
tiated flu-like symptoms to a septicemic purpural rash and
shock within hours. As with septic shock, hypotension and
ARDS are common, as well as renal failure, adrenal infarc-
tion and acute adrenal crisis. Severe coagulopathy (DIC) is
particularly noted in meningococcemia. Even in cases
where the illness is not fatal, it may result in serious mor-
bidity such as stroke or tissue necrosis that requires extrem-
ity amputations.
Systemic meningococcal disease is marked by some of the
highest levels of circulating endotoxin documented in any
illness, and mortality appears to correlate with the endotox-
in (and bacterial) load (Brandtzaeg). Although appropriate
antibiotic therapy is largely effective in eradicating the
causative organism (penicillin-resistant strains are emerg-
ing, however), the endotoxin-related complications can still
progress. Thus, current investigational efforts to treat this
devastating illness include using a recombinant BPI protein
to eliminate the bacterial endotoxin as well as the
N.
meningitidis
bacteria. (Giroir). Other investigational
approaches target the coagulopathy (activated Protein C) or
individual mediators in the sepsis cascade (TNF, etc.).
V. Other Clinical Conditions
A. Complications That May Be Associated With
Gut Translocation
Clinicians have long recognized that patients without defin-
itive proof of either local or bacteremic Gram-negative
infection suffer SIRS and other complications that are pre-
sumptively of infectious origin. This problem (which
reflects the diagnostic gap discussed above) in part fuels
the interest in translocation. This section summarizes those
clinical syndromes in which this mechanism has the most
theoretical appeal and/or experimental support: trauma, car-
diovascular surgery associated with intestinal ischemia, and
burns. Interestingly, these are also conditions in which the
normal host response to bacteria or endotoxin may be
impaired-by immunosuppression or RES dysfunction, for
example-thereby facilitating the consequences of bacterial
and endotoxin translocation. (Hiki, Rocke).
Trauma
Many patients suffering from trauma have the course of ill-
ness complicated by SIRS, organ dysfunction or sepsis.
When severe blood loss associated with trauma causes
hemorrhagic shock, the results may include splanchnic
ischemia and the subsequent release of endotoxin from the
gut (Saadia). Secondary endotoxemia appears to be a plau-
sible link between translocation and post-trauma organ fail-
ure (Moore). The emergence of infectious complications
post-trauma has been associated with multiple blood trans-
fusions (Agarwal). Various investigations have demonstrat-
ed increased intestinal permeability in trauma victims
(Reed, Faries), the post-trauma appearance of IgM anti-
endotoxin antibodies in one small series (Hiki), and the
microscopic demonstration of bacterial translocation to
mesenteric lymph nodes in trauma patients (Langkamp-
Henken).
While none of these studies have demonstrated a causal
relationship between translocation and septic complica-
tions, an intriguing recent investigation of patients suffering
severe trauma found strong positive correlations between
increases in intestinal permeability post-trauma and four
separate clinical parameters: the severity of trauma (based
on standard assessment scales); multiple organ dysfunction
Other Clinical Conditions
Page 20
15
scores; the ultimate development of SIRS; and the inci-
dence of infectious complications (Faries).
A recent study in 400 trauma patients who received more
than two units of blood showed an association between
blood loss/replacement and infectious complications,
including pneumonia, bacteremia and DIC (Smith). That
same study also showed a statistically-significant reduction
in pneumonia and ARDS incidence in patients receiving an
endotoxin-neutralizing BPI-derived drug.
Cardiovascular Surgery
In adults and children undergoing cardiovascular surgery,
endotoxin, presumptively derived via gut translocation,
may trigger an abnormal inflammatory response, delayed
recovery and other post-operative complications, and per-
haps even sepsis (Andersen, Baigrie, Casey, Martinez-
Pellus, Riddington, Rocke, Roumen & Freiling, Watarida).
Studies have shown the presence of circulating endotoxin
and TNF in pediatric patients following open-heart surgery
(Casey), and circulating endotoxin in adults undergoing
cardiopulmonary bypass surgery (Andersen, Rocke).
Investigators have postulated that these findings relate to
the decrease in mesenteric circulation that occurs during
aortic cross-clamping and cardiopulmonary bypass, and
have suggested that measures which protect the gut mucosa
could prevent perioperative endotoxemia (Riddington,
Watarida). Although endotoxemia has not been unequivo-
cally implicated as a cause of morbidity in cardiac surgery
(Oudemans-van Straaten), one group has reported that low
preoperative titers of endogenous anti-endotoxin antibodies
(which may reflect impaired host immunity to endotoxin)
may predict adverse outcomes (Bennett-Guerrero).
Similarly, abdominal aortic surgery is associated with mul-
tiple events that can impair splanchnic perfusion during
surgery, cause gut ischemia and consequently induce sys-
temic bacterial translocation (Baigrie, Taggart). Such
events include hypotensive episodes during the surgery, the
use of aortic cross-clamping procedures that reduce blood
flow to the mesenteric circulation, and reperfusion follow-
ing ischemia which may release oxygen free radicals and
exacerbate the mucosal damage (Baigrie, Rocke, Saadia).
Elevated cytokines (IL-1
, IL-6, TNF
) have been
observed in patients undergoing elective abdominal aortic
repair as well as in those suffering hemorrhagic shock
caused by ruptured abdominal aortic aneurisms, but the
correlation with endotoxemia was unclear. (Roumen
et al
.)
Despite a number of published observations about these
phenomena, it is still unclear whether they represent clini-
cally relevant occurrences of endotoxin-associated disease
in these patients or whether they are "experiments of
nature" in which to study endotoxemia during highly
controlled episodes of gut hypoperfusion.
Burns
In the case of burns, most occurrences of Gram-negative
bacterial sepsis can be attributed to contaminated burn
wounds (Saadia). Yet many burn-related sepsis cases occur
without an apparent external source of infection, leading
investigators to postulate translocation as causal (Jones II
[a]; Jones II [b]). Severe fluid loss or shock associated with
an extensive burn may cause intestinal ischemia and thus
impair the normal gut barrier to translocation. Animal
experiments have shown translocation of microorganisms
and endotoxin from the gut to the mesenteric lymph nodes,
distant organs and the systemic circulation after burn injury
(Hansbrough). In addition, burns can lead to the activation
of neutrophils capable of injuring endothelial cells and
damaging the gut mucosa, further facilitating bacterial or
endotoxin translocation (Jones II [b]; Hansbrough).
Summary
The phenomenon of gut translocation is well established in
animal and human studies. Various animal models suggest
that when a focal or systemic infection is not apparent, bac-
terial translocation is the most likely source of endotoxin.
However, there is not yet a consensus on its clinical rele-
vance in humans. Further research is needed to clarify the
clinical significance of translocation.
B. Local and Organ-Specific Diseases
As indicated above, the past two decades have seen signifi-
cant effort directed to the understanding and treatment of
life-threatening systemic illnesses caused by Gram-negative
organisms and their endotoxins. More recently, however,
there has been a growing appreciation of the potential of
endotoxin to cause or contribute to the pathogenesis of a
heterogeneous group of other illnesses. In some cases,
these are illnesses of obscure cause; in others, the cause is
Other Clinical Conditions
Page 21
16
fairly well understood. Most are local rather than systemic
diseases, or at least have predominantly localized manifes-
tations. In general, the literature about endotoxin associa-
tion in these diseases is more preliminary than the
established consensus that exists in the field of sepsis.
Additional research will be needed to clarify clinical signif-
icance. Nevertheless, as more sophisticated investigational,
diagnostic, and therapeutic techniques emerge, these ill-
nesses may represent a new frontier for therapeutic inter-
vention directed against possible endotoxin-related human
pathology.
The sections that follow summarize selected literature in
this emerging area, with disease states grouped by the
organ system most prominently affected.
1. Digestive
*
Inflammatory Bowel Disease (Crohn's Disease and
Ulcerative Colitis)
The precise pathogenic role of systemic endotoxemia
in inflammatory bowel disease remains unclear.
Circulating endotoxin has been detected in patients
with Crohn's disease and ulcerative colitis (Gardiner,
van Deventer, Wellman). One study also found anti-
bodies to endotoxin as well as endotoxin itself in
ulcerative colitis and Crohn's disease patients (Aoki).
It is not yet known if circulating LPS has a pathogen-
ic role in these illnesses and their systemic manifesta-
tions, or if its presence is simply the consequence of
damaged intestinal mucosa.
*
Neonatal Necrotizing Enterocolitis (NEC)
As more and smaller premature infants survive, NEC
is emerging as a significant cause of morbidity and
mortality in neonatal intensive care units (Kliegman).
Premature and low birth weight infants are at risk for
this disease, which is a frequent cause of death (10-
50% mortality) usually as a result of peritonitis and
sepsis. The pathogenic role of endotoxin has been
investigated in this disease that, like inflammatory
bowel disease, involves a gross impairment of the gut
mucosal barrier. Endotoxemia has been noted in NEC
infants, with an additional association with thrombo-
cytopenia (Scheifele). Three potential sources of
endotoxin have been identified in NEC patients: focal
infection (usually peritonitis), bacteremia, and the gut
itself (Scheifele). Various animal models suggest that
when a focal or systemic infection is not apparent,
bacterial translocation is the most likely source of
endotoxin. The risk factors for bacterial translocation
are also risk factors for NEC, namely, impaired gut
mucosal barrier function, intestinal bacterial over-
growth and impaired (or premature) host immune
defenses (Deitch). An additional study examined
inflammatory mediators in NEC and demonstrated
elevated TNF and PAF (platelet-activating factor),
although neither predicted disease severity or out-
come (Caplan). As with IBD, the actual role of endo-
toxin remains to be fully elucidated.
*
Acute Pancreatitis
Most of the mortality in this disease (5-40%) is
caused by septic complications. These are clinically
similar to those seen after burns, trauma and surgery.
Therefore, intestinal bacterial translocation has been
considered as a possible cause of infectious compli-
cations in pancreatitis. Alterations in levels of anti-
bodies to lipid A and high levels of circulating
endotoxin also suggest that endotoxin may be a factor
in the pathogenesis of acute attacks (Curley). The
role of bacteria and endotoxin in pancreatitis is still
under investigation.
*
Liver Disease
Clinical observations of elevated LPS levels in
patients with cirrhosis, alcoholic liver disease,
obstructive jaundice, and other hepatic conditions
have led many investigators to suggest that endotoxin
may be a factor in the development of numerous liver
diseases and/or their complications (Bode, Fukui,
Schafer), and that treatment to eliminate circulating
LPS may have therapeutic benefit (Liehr). Patients
with non-alcoholic and alcoholic liver disease fre-
quently have depressed Kupffer cell function and/or
the presence of vascular shunts that enable endotoxin
to pass into the systemic circulation (Odeh). One
investigator has hypothesized that the resulting sys-
temic endotoxemia may trigger the release of TNF
and leukotrienes, which can cause liver damage
above and beyond that caused directly by alcohol or
other toxic metabolites (Fukui). Another group has
Other Clinical Conditions
Page 22
17
reported that circulating endotoxin may contribute to
renal impairment occurring in patients with either cir-
rhosis or obstructive jaundice (Wilkinson). And while
speculative, endotoxemia and excess TNF in patients
with acute and chronic liver diseases have also been
postulated to cause or exacerbate hepatic
encephalopathy (Odeh; Wellman).
*
Periodontal Disease
Endotoxin has been implicated as one of several
potential bacterial mediators in the development of
periodontal disease (Loesche). Gram-negative bacte-
ria and endotoxin that accumulate on the tooth sur-
face can penetrate the crevicular fluid and gingival
epithelium. The ensuing local inflammatory response,
in synergy with other bacterial toxins and destructive
enzymes, can result in the soft tissue loss and bone
destruction that characterize severe periodontitis
(Loesche, Wilson). Periodontal disease has also been
associated with cardiovascular disease, presumably
through inflammation triggered by the gram-negative
organisms entering the general circulation from the
gums (Genco). The role of bacterial endotoxin in
periodontal disease remains under investigation.
2. Respiratory
*
Cystic Fibrosis
Cystic Fibrosis (CF) patients have a genetic defect of
the calcium channel that produces abnormally vis-
cous mucus in the digestive system and the lungs.
This predisposes these patients to recurring (and
eventually fatal) lung infections, usually caused by
Gram-negative bacteria such as
Pseudomonas aerugi-
nosa.
Recent studies suggest that endotoxemia may
be associated with acute exacerbations of CF. LPS
and IL-1 appear in the plasma of CF patients during
acute episodes of increased pulmonary inflammation,
and elevated LPS levels decreased significantly fol-
lowing two weeks of intravenous antibiotic therapy
(Wilmott).
*
Asthma
The observation that endotoxin exposure can cause
wheezing and other respiratory symptoms in sensitive
individuals has led several investigators to suggest
that it may play a role in the onset or worsening of
asthma (Dubin, Jagielo). One theory proposes that
LPS, LBP and soluble CD14 are all present in the
airways of asthmatic patients in low concentrations.
An antigen challenge may lead to increased levels of
LBP and CD14 and therefore trigger a magnified
inflammatory response to inhaled LPS (Dubin).
Additional studies of asthma and endotoxin exposure
report that aerosolized endotoxin exposure correlated
with decreases in pulmonary function in fiberglass
wool factory workers (Milton), and that allergenic
pollen may be contaminated with bacterial endotoxin
in the absence of viable bacteria (Spiewak). Endo-
toxin has also been detected in asthma-associated
house dust (Michel).
3. Cardiovascular
*
Coronary Artery Disease
Two Gram-negative human pathogens,
Helicobacter
pylori
and
Chlamydia pneumoniae
, that bear LPS-
like antigens, have been epidemiologically associated
with the presence of coronary artery disease;
seropositivity to either microorganism is an indepen-
dent risk factor for electrocardiographic abnormali-
ties (Patel). Since LPS exposure induces the
production of inflammatory mediators that have been
implicated in atherogenesis (Marcus), endotoxin may
therefore be linked to atherosclerosis, although this
hypothesis is at present very controversial.
4. Renal
*
Hemolytic Uremic Syndrome
Escherichia coli
O157:H7, the enteropathogenic
organism associated with several recent national out-
breaks of serious illness and death, causes a life-
threatening hemolytic uremic syndrome (HUS)
characterized by acute renal failure, hemolytic ane-
mia, thrombocytopenia and hemorrhagic colitis
(Kaplan). Animal models have shown that LPS and
Shiga-like toxins, both produced by this strain of
E. coli
, may contribute to nephropathology, gastroin-
testinal abnormalities, and death (Karpman).
Furthermore, the presence of anti-
E. coli
LPS anti-
bodies in patients with HUS is frequent enough
(>70%) to have been proposed as a diagnostic tool in
this illness (Greatorex). Intriguingly, similar antibody
Other Clinical Conditions
Page 23
18
responses have been observed in patients with HUS
caused by non-O157
E. coli
strains (Ludwig).
*
Complications of Renal or Peritoneal Dialysis
Patients undergoing renal or peritoneal dialysis may
be exposed to microbial contaminants, such as Gram-
negative bacteria and their components, in dialysis
fluids or on dialysis membranes (Bottalico, Perez-
Garcia). One study found that circulating TNF and
IL-6 levels were highest in patients on chronic
hemodialysis and receiving contaminated dialysate
(Perez-Garcia). It has been hypothesized that
cytokine release, possibly due to this presence of
Gram-negative bacteria and/or endotoxin in the
dialysate, may contribute to long-term complications
in patients on hemodialysis or chronic peritoneal
dialysis (Sundaram).
5. Immunologic
*
Autoimmunity and Rheumatoid Arthritis
The ubiquity of endotoxin, which is present in food,
water, and certain vaccines-not to mention its con-
stant production in, and shedding from, the gastroin-
testinal tract-has led to speculation that LPS may
play a role in the development or continuation of
autoimmunity. The lipid A component of endotoxin,
when free, can be adsorbed onto phospholipid cell
membranes. The resulting novel configuration may
induce the production of autoimmune IgM antibodies
against surface antigens, including phospholipids
(van Rooijen). In rheumatoid arthritis, synovial
fibroblasts exhibit increased sensitivity to LPS in the
presence of soluble CD14 and LBP (Yu).
6. Cancer
*
Cancer and Chemotherapy
Immunocompromised cancer patients are at high risk
of infectious complications, including gram-negative
sepsis (Easson). Both radiation and chemotherapy
treatment have direct cytotoxic impact on the GI
tract, suggesting that bacterial translocation may be
implicated in the development of septic complica-
tions. Investigations in specific cancers show that
hepatic, gastrointestinal and hematological cancers
show a strong association with elevated endotoxin
levels (Easson, Yoshida, Amati, Engervall), especial-
ly in patients receiving chemotherapy or radiation. In
patients with chemotherapy-induced neutropenia and
fever, elevated endotoxin was detected in 60% of
patients, with the highest values in patients with
Gram-negative bacteremia (Engervall). DIC in can-
cer patients is most frequently found in biliary, gas-
tric, hepatic and pancreatic cancer; endotoxemia was
more frequently detected in those who received
chemotherapy (Okubo). At present, while there is
evidence of an association between cancer and endo-
toxin, it remains to be shown what the clinical signif-
icance of that association is.
VI. Current Treatment of Sepsis
Returning to the most dramatic and challenging of the
endotoxin-related syndromes, Carcillo and Cunnion have
presented a conceptual framework for the treatment of sep-
sis and septic shock in both children and adults (Carcillo).
Early recognition depends upon a high index of suspicion
and a clinical appreciation of common and uncommon
diagnostic findings, so that early treatment (i.e. antibiotics)
may be initiated and later complications avoided. Once
septic shock occurs, however, these authors divide therapy
into two phases: immediate resuscitation and stabilization.
The objective of immediate resuscitation is to control the
patient's acute clinical condition and allow time for diag-
nosis, more sophisticated treatment, and eventual long-
term stabilization. The airway must be secured, which can
include intubation and ventilation in the case of respiratory
failure or severe acidosis. Volume resuscitation is aimed at
restoring blood pressure, and may involve crystalloids, col-
loids, and/or blood products for both children and adults.
When the response to fluids is unsatisfactory, invasive
hemodynamic monitoring is indicated and treatment with
vasopressor and inotropes, such as dopamine, norepineph-
rine, or dobutamine, is begun. And, of utmost importance,
antibiotic therapy is initiated urgently. Most often, patients
are started on an empiric, broad-spectrum antibiotic regi-
men; however, if the source of infection and responsible
organism are already known, specifically-targeted antibiot-
ic therapy can be given (Carcillo, Ognibene).
Current Treatment
Page 24
19
With resuscitation underway, attention is then turned to
preventing, or at least ameliorating, the potentially devas-
tating downstream complications of shock. Respiratory and
cardiovascular status is fine-tuned, and blood gases and
blood pressure are optimized to the extent possible.
Cultures and sensitivity determinations, invasive diagnostic
procedures and even surgical exploration, if necessary, are
performed to confirm the presence and type of infection
and to direct definitive antibiotic therapy. Renal failure, if
not prevented by aggressive fluid therapy, is managed as
appropriate (e.g., peritoneal or hemodialysis), while due
consideration is given to the patient's electrolyte balance
and nutritional status (Carcillo).
In summary, the contemporary care of the patient with sep-
tic shock is primarily supportive; although antibiotics are
always used in those cases with diagnosable infection and
frequently used even if an infecting organism cannot be
identified (i.e., fever of unknown origin, SIRS with shock).
In a sense, current therapeutic options address only the
extremes of the syndrome: antibiotics target the initiating
event (bacterial infection), while supportive care deals with
the end stages (shock and organ failure).
With the increasing incidence of SIRS, sepsis and septic
shock, and the growing knowledge of the pathogenic
events underlying these syndromes, numerous laboratories
and investigators around the world are attempting to devel-
op innovative and targeted therapies to address the cascade
of events that occurs between infection and shock.
VII. Future Directions in the Treatment of
Sepsis and Septic Shock
For more than a decade, research and clinical investigators
have attempted to develop a new generation of therapeutics
that go beyond the current nonspecific regimens of broad-
spectrum antibiotics and physiologic support. These newer
products, rather than treating advanced, or even end-stage,
clinical manifestations of sepsis, are aimed much more
selectively at proximate steps in the pathogenic pathway.
Agents undergoing development at present are, for the most
part, specific inhibitors, blockers or neutralizers of bio-
chemical mediators of the systemic inflammatory response,
using the rationale that interrupting the events of the
inflammatory cascade will help prevent or ameliorate cata-
strophic sepsis.
Although a vast array of pathways have also attracted the
attention of the pharmaceutical and biotechnology indus-
tries, the most frequently addressed targets for drug inter-
vention thus far have been the LPS molecule itself, and two
of the major effectors induced by LPS, TNF and NO
(Baumgartner, Cavaillon, Verhoef). Unfortunately, to date,
none of those attempts to block the systemic inflammatory
cascade have succeeded in demonstrating a survival benefit
in clinical trials. The lack of successful drug development
in the medical arena stems from two general issues:
1) The redundancy of the cascade makes interfering with a
single downstream mediator such as TNFa, IL-1, IL-8, NO,
etc. (the focus of numerous drug development programs)
an unlikely means of altering the complex course of the
syndrome.
2) Appropriate clinical trial design remains problematic
because of several critical, but to date uncontrollable, vari-
ables in trial conduct, including:
* Heterogeneous patient populations with many different
underlying and overlying diseases with their own intrin-
sic mortality rates.
* Various (and not necessarily documentable) infectious
sources, including Gram-positive and fungal infections,
the presence of neither of which eliminates the possibili-
ty of a concomitant cryptic Gram-negative infection
(e.g., gut translocation).
* The time lag between the actual onset of the inflamma-
tory response, clinical diagnosis and initiation of
therapy, superimposed on variable rates of sepsis pro-
gression from patient to patient.
* The use of a 28-day, all-cause mortality endpoint based
on old study designs that have become dogma with
investigators and regulators.
Of course, for treating endotoxemia, the most compelling
therapeutic strategy would seem to be eliminating endotox-
in itself such that the induction and maintenance of the sys-
temic inflammatory response and the catastrophic cytokine
avalanche can be avoided or substantially ameliorated.
Future Directions
Page 25
20
To date, attempts to detoxify endotoxin have been done
using monoclonal anti-LPS antibodies (E-5
®
and HA-1A or
Centoxin
®
). However, in large placebo-controlled trials,
both antibodies failed to consistently reduce 28-day mortal-
ity in patients with sepsis, including septic shock (Bone,
McCloskey). The negative HA-1A experience has also been
confirmed in a retrospective observational study (National
Committee for Evaluation of Centoxin). Many attribute
these failures not to a focus on the wrong target but rather
to flaws, perhaps unavoidable, in the clinical trial designs.
Furthermore, while these early antiendotoxin agents assist-
ed in clearance, they did not neutralize the biological prop-
erties of LPS
in vivo.
One of the most important downstream mediators of sepsis,
TNF, has also been heavily targeted for therapeutic inter-
vention. At least six recent human clinical trials have stud-
ied various forms of anti-TNF monoclonal antibodies in
sepsis, all with the same disappointing results (Ognibene).
Although these antibodies were fairly effective at neutraliz-
ing the target cytokine, in general, 28-day all-cause mortal-
ity rates were equivalent in the treated and placebo groups,
again highlighting the methodological difficulties which
plague the anti-endotoxin trials.
Taken together, these results demonstrate that sepsis, as a
complication of many diseases, is an extremely complex
area both medically and in terms of clinical investigation.
To put some perspective on the difficulty of developing
new therapies for sepsis and septic shock, one author has
calculated that there have been at least 13 failed Phase III
trials of various agents, in an aggregate population of
10,864 patients (Scannon).
Fortunately, past experience has not totally constrained the
development of new therapies. Perhaps the most important
lesson from the failed studies is that there is a great need
for standardization in the conduct of clinical trials in sepsis.
Standardization of patient populations, disease definitions,
outcome variables, study designs and statistical approaches
are crucial to bringing much-needed new therapeutics to
market, as is a fundamental understanding of a therapeutic
molecule's strengths and weaknesses. Certainly, the lessons
learned during the early trial failures will provide a better
road map for future clinical investigations. The time may
soon come when treatments for sepsis are far more sophis-
ticated and specific than antibiotics and supportive care.
VIII. Conclusion: Beyond Sepsis
Equally important in fostering the seeds of optimism in this
area are emerging concepts which may alter the way sepsis
and related diseases are viewed and approached by the clin-
ician and by the pharmaceutical researcher. For example, to
the extent that bacterial endotoxin not only induces an
inflammatory response but must remain present to perpetu-
ate the cascade, focus should turn to earlier recognition and
specific endotoxin-neutralization therapy. The development
of better diagnostics could facilitate earlier, better-targeted
treatment not only for sepsis, but for the many diseases that
predispose for septic complications. Likewise, the apprecia-
tion that septic shock lies at the far end of a continuum of
clinical manifestations of the inflammatory response to
bacteria and endotoxin will direct attention to preventative
measures to treat at-risk patients. New paradigms may lead
to new approaches to clinical strategy, such as performing
smaller clinical studies in well-characterized patient popu-
lations (e.g., severe pediatric meningococcemia rather than
all-comers sepsis) to provide meaningful early data on the
efficacy of new drugs.
Beyond bettering the ongoing search for an approvable sep-
sis product is a whole frontier of pharmaceutical research
that investigates therapies in a broader category of systemic
inflammatory reactions to bacteria and endotoxin. New
therapeutic approaches to treating earlier-stage infectious
complications such as those that follow surgery and trauma
may prevent at-risk patients from progressing to sepsis at
all. In addition, patients suffering from a number of other
diseases in which Gram-negative bacteria and endotoxin
are found to be important primary or complicating factors
could benefit greatly from new treatments that target
inflammatory mediators or endotoxin itself, in addition to
the standard treatment of antibiotics and medical support.
The most fruitful approach may therefore be to redefine the
medical targets altogether, instead of attempting to treat
complex multifactorial syndromes with a "one size fits all"
approach.
Beyond Sepsis
Page 26
21
Glossary
Acute Renal Failure (ARF):
sudden and severe failure of
kidney function, one of several organ failures associated
with later stages of
sepsis.
Treatment of ARF requires care-
ful metabolic support, up to and including dialysis. ARF
may be a manifestation of the
Multiple Organ
Dysfunction Syndrome.
Acute Respiratory Distress Syndrome (ARDS):
severe
respiratory dysfunction, characterized by lung inflamma-
tion, increased permeability of lung capillaries, pulmonary
edema and inadequate pulmonary gas exchange. It may be
caused by direct lung trauma (e.g., drowning, inhalation of
toxins) or by indirect systemic mechanisms such as inflam-
matory processes related to infections or sepsis. ARDS may
be a manifestation of the
Multiple Organ Dysfunction
Syndrome.
arachidonic acid:
a phospholipid fatty acid molecule,
released from membranes of white blood cells and other
cells active in host defense. Arachidonic acid and many of
its metabolites, including prostaglandins and leukotrienes,
mediate local and systemic inflammatory reactions.
bacteremia:
literally "bacteria in the blood"; a bacterial
infection originating in or spreading to the bloodstream.
BPI (bactericidal/permeability-increasing protein):
a
host-defense protein produced by polymorphonuclear leu-
cocytes. It binds to
endotoxin
on or from
Gram-negative
bacteria
, killing the bacteria. It neutralizes endotoxin by
binding to
LPS
or
LOS
molecules with higher affinity than
LBP
(with which it shares considerable homology).
CD14:
a receptor produced by monocytes and displayed on
cell membranes as well as being shed into the bloodstream.
The CD14 molecule binds the
LPS-LBP
complex and initi-
ates the
inflammatory cascade.
cascade:
a complex sequence of events characterized by
multiple positive and negative feedback loops of biologi-
cally active molecules (such as
cytokines, complement,
and
coagulation
factors). Each component of the cascade
is activated and/or suppressed by previous components, and
in turn activates and/or suppresses later components.
coagulation cascade:
the series of tissue-based and circu-
lating molecules which are activated in sequence to cause
blood clotting (coagulation).
complement, complement cascade:
a system of at least 15
naturally-occurring plasma proteins (complement proteins)
which play a role in host defense and mediate a number of
inflammatory reactions.
cytokines:
signaling chemicals involved in inflammation,
such as interleukins (e.g., IL-1, IL-6), interferons, and
tumor necrosis factor (TNF). Cytokines are released by
macrophages, lymphocytes, and other cells in response to
pro-inflammatory stimuli such as infectious organisms or
endotoxin.
disseminated intravascular coagulation (DIC):
a syn-
drome of generalized activation of
coagulation
factors,
leading to clinical manifestations of inappropriate clotting,
bleeding, and shock.
endotoxin (lipopolysaccharide, LPS):
lipopolysaccharides
are complex molecules composed of "fat plus many sug-
ars". The LPS molecule is a structural part of the cell wall
in Gram-negative bacteria. Endotoxin initiates a potentially
catastrophic
inflammatory cascade
that can lead to
sepsis,
shock, organ failure and death. Additional endotoxic mem-
brane molecules include
lipooligosaccharide (LOS)
and
lipoproteins.
endotoxemia:
the detectable presence of
endotoxin
in the
bloodstream.
exotoxin:
pathogenic chemicals secreted by bacteria such
as the Shiga-like toxin produced by
E. coli
O157:H7 or the
toxic shock molecule produced by certain strains of
Staphlococcus aureus.
Glossary
Page 27
22
Gram-negative bacteria:
the Gram stain is a microscopic
viewing technique that distinguishes two types of bacteria.
Gram-positive bacteria stain blue when prepared with
Gram stain. Gram-negative bacteria do not take up the stain
and appear pink or red under the microscope because their
outer membrane, with its
lipopolysaccharide (LPS)
struc-
tural component, is resistant to absorbing the stain. Gram-
negative bacteria are frequently implicated infectious
agents in various local and systemic infections, including
sepsis.
They are also the primary microbial population in
the intestines and are therefore a potentially complicating
factor in other infections as well as in trauma and surgery
(see
intestinal translocation
).
inflammation:
a multifactorial cellular and humoral host
defense response classically characterized by redness,
swelling, warmth, and pain when confined to a local area.
Systemic activation of the inflammatory response, howev-
er, can manifest as fever, shock, organ dysfunction, and
even death (see
sepsis
and
Systemic Inflammatory
Response Syndrome
).
inflammatory cascade:
the specific systemic
cascade
induced in response to infection or exposure to infectious
organisms. Clinical signs range from none through fever,
malaise, hypo- or hyper-tension, and tachycardia, to shock,
multiple organ failure and death. See also
Systemic
Inflammatory Response Syndrome (SIRS)
.
intestinal translocation:
the transfer of bacteria or their
breakdown products, including endotoxin, across the
mucosa of the gastrointestinal tract to the systemic circula-
tion. When normal host mechanisms which modulate the
process fail, bacteria and/or their endotoxins may trigger a
systemic inflammatory response.
lipid A:
the lipid portion of
endotoxin
that is responsible
for its toxicity by binding to
LBP
and inducing the inflam-
matory cascade.
lipooligosaccharide (LOS):
short chain
endotoxin
; found
in
N. meningitidis
bacteria that cause meningococcemia.
lipopolysaccharide (LPS):
long chain
endotoxin
; the most
common form in
Gram-negative bacteria
.
lipopolysaccharide binding protein (LBP):
An acute-
phase plasma protein that binds to endotoxin. The LBP-
LPS complex binds to the
CD14
receptor on macrophages,
triggering cytokine release and initiating the
inflammatory
cascade
.
Multiple Organ Dysfunction Syndrome (MODS):
in
acutely ill patients altered function of multiple organs-
such as the kidneys, lungs, liver, and central nervous
system-as defined by the inability to maintain normal
homeostasis in the absence of medical intervention.
Primary MODS is the result of a direct insult to the organs.
Secondary MODS is the consequence of the systemic
inflammatory response.
sepsis:
a systemic response to infection; a syndrome char-
acterized by a culture-documented infection and two or
more of the following signs and symptoms: hyper- or
hypothermia, tachycardia, hyperventilation and leukocyto-
sis or leukopenia.
septic shock:
septic shock refers to the most severe form
of sepsis, characterized by refractory hypotension, clinical
evidence of organ hypoperfusion, and/or organ dysfunction
in the presence of a documented infection.
SIRS (Systemic Inflammatory Response Syndrome):
the
systemic inflammatory response, to a variety of severe clin-
ical insults. Characterized by fever or hypothermia, tachy-
cardia, tachypnea, abnormal white cell count. Differs from
sepsis only in that the term SIRS is used in the absence of a
documented infection.
Glossary
Page 28
23
Agarwal N; Murphy JG; Cayten CG, Stahl WM. Blood transfu-
sion increases the risk of infection after trauma. Archives of
Surgery. 1993; 128:171-177.
Amati L; Caradonna L, Greco B, Leo S, Caccavo D, Jirillo E.
Impairment of phagocytic and T-cell-mediated antibacterial activi-
ty and plasma endotoxins in patients with untreated gastrointestinal
cancer. Scand Journal of Gastroenterology. 1998; 33(8):847-52.
American College of Chest Physicians/Society of Critical Care
Medicine. Definitions for sepsis and organ failure and guidelines
for the use of innovative therapies in sepsis. Crit Care Med. 1992;
20(6):864-74.
Andersen L; Baek L; Degn H; Lehd J; Krasnik M, and Rasmussen
J. Presence of circulating endotoxins during cardiac operations. J
Thorac Cardiovasc Surg. 1987; 93:115-9.
Antonsson J and Fiddian-Green G. The role of the gut in shock
and multiple system organ failure. Eur J Surg. 1991; 157:3-12.
Aoki K. A study of endotoxemia in ulcerative colitis and Chrohn's
disease. I. Clinical study. Acta Medica Okayama. 1978;
32(2):147-58.
Baigrie R; Lamont P; Whiting S, and Morris P. Portal endotoxin
and cytokine responses during abdominal aortic surgery. Am J
Surg. 1993; 166:248-51.
Baumann H and Gauldie J. The acute phase response. Immunol
Today. 1994; 15(2):74-80.
Baumgartner J and Glauser M. Immunotherapy of endotoxemia
and septicemia. Immunobiol. 1993; 187:464-77.
Beamer L; Carroll S, and Eisenberg D. Crystal structure of human
BPI and two bound phospholipids at 2.4 angstrom resolution.
Science. 1997; 276:1861-4.
Bennett-Guerrero E; Ayuso L; Hamilton-Davies C; White W;
Barclay R; Smith P; King S; Muhlbaier L; Newman M, and
Mythen M. Relationship of preoperative antiendotoxin core anti-
bodies and adverse outcomes following cardiac surgery. JAMA.
1997; 227(8):646-50.
Berg RD. Bacterial translocation from the gastrointestinal tract.
Journal of Medicine. 1992; 23(3 & 4):217-244.
Bode C; Fukui H, and Bode CJ. `Hidden' endotoxin in plasma of
patients with alcoholic liver disease. Eur J of Gastroenterol
Hepatol. 1993; 5:257-62.
Bone R. The pathogenesis of sepsis. Ann Int Med. 1991;
115(6):457-69. [a]
Bone R; Balk R; Cerra F; Dellinger P; Fein A; Knaus W; Schein
R, and Sibbald W. Definitions for sepsis and organ failure and
guidelines for the use of innovative therapies in sepsis. Chest.
1992:1644-56. [b]
Bone R; Balk R; Fein A; Perl T; Wenzel R; Reines D; Quenzer R;
Iberti T; Macintyre N, and Schein R. A second large controlled
clinical study of E5, a monoclonal antibody to endotoxin: results
of a prospective, multicenter, randomized, controlled trial. Crit
Care Med. 1995; 23(6):994-1006. [c]
Bottalico D; Pertosa G; Gesualdo L, and Schena F. Endotoxins
may modulate tumor necrosis factor alpha (TNFa) and inter-
leukin-6 (IL-6) release by monocytes (Mø) from uremic patients.
Kidney Internat. 1993;44:1392-3.
Brandtzaeg P; Kierulf P; Gaustad P; Skulberg A; Bruun J;
Halvorsen S, and Sorensen E. Plasma endotoxin as a predictor of
multiple organ failure and death in systemic meningococcal dis-
ease. J Infect Dis. 1989; 159(2):195-204.
Brathwaite C; Ross S; Nagele R; Mure A; O'Malley K, and
Garcia-Perez F. Bacterial translocation occurs in humans after
traumatic injury: evidence using immunoflourescence.
J Trauma. 1993; 34(4):586-90.
Brewster D; Franklin D; Cambria R; Clement Darling R;
Moncure C; Lamuraglia G; Stone W, and Abbott W. Intestinal
ischemia complicating abdominal aortic surgery. Surgery. 1991;
109(4):447-54.
Caplan MS; Hsueh W. Necrotizing enterocolitis: Role of platelet
activating factor, endotoxin, and tumor necrosis factor. J Pediatr.
1990; 117(1 Pt 2):S47-51.
Carcillo J and Cunnion R. Septic shock. Crit Care Clin. 1997;
13(3):553-74.
Carroll SF; Dedrick RL; White ML. Plasma levels of lipopolysac-
charide binding protein (LBP) correlate with outcome in sepsis
and other patients. Sixth Vienna Shock Forum. 1997; abs. 101.
Casey W; Hauser G; Hannallah R; Midgley F, and Khan W.
Circulating endotoxin and tumor necrosis factor during pediatric
cardiac surgery. Crit Care Med. 1992; 20(8):1090-6.
Cavaillon J. Controversies surrounding current therapies for sepsis
syndrome. Bull Inst Pasteur. 1995; 93:21-41.
Cohen J and Carlet J. INTERSEPT: an international, multicenter,
placebo-controlled trial of monoclonal antibody to human tumor
necrosis factor-a in patients with sepsis. Crit Care Med. 1996;
24(9):1431-40.
Colman R. The role of plasma proteases in septic shock. N Engl J
Med. 1989; 320(18):1207-9.
Curley PJ. Endotoxin, cellular immune dysfunction and acute
pancreatitis. Annals of the Royal College of Surgeons of England.
1996; 78(6):531-535.
Danner R; Elin R; Hosseini J; Wesley R; Reilly J, and Purillo J.
Endotoxemia in Human Septic Shock. Chest. 1991; 99(1):169-75.
References
Page 29
24
References
de Warra I; Jaccard C; Betz-Corradin S; Chiolero R; Yersin B;
Gallati H; Assicot M; Bohuon C, and Baumgartner J. Cytokines,
nitrite/nitrate, soluble tumor necrosis factor receptors, and pro-
cacitonin concentrations: comparisons in patients with septic
shock, and bacterial pneumonia. Crit Care Med. 1997; 25(4):607-13.
Dedrick R and Conlon P. Prolonged expression of lipopolysaccha-
ride (LPS) induced inflammatory genes in whole blood requires
continual exposure to LPS. Infect Immun. 1995; 63(4):1362-8.
Deitch E. Bacterial translocation of the gut flora. J Trauma. 1990;
30(12):S184-S189.
Dubin W; Martin T; Swoveland P; Leturq D; Moriarity A; Tobias
P; Bleecker E; Goldblum S, and Hasday J. Asthma and endotoxin:
lipopolysaccharide-binding protein and soluble CD14 in bron-
choalveolar compartment, Am J Physiol. 1996; 270. L736-44.
Easson AM; Bode BP, Fischer CP, Souba WW. Effects of endo-
toxin challenge on hepatic amino acid transport during cancer.
Journal of Surg Research. 1998; 77(1):29-34.
Elin R; Robinson R; Levine A, and Wolff S. Lack of clinical use-
fulness of the limulus test in the diagnosis of endotoxemia. N
Engl J Med. 1975; 293(1):521-4.
Elsbach P. Bactericidal permeability-increasing protein in host
defence against gram-negative bacteria and endotoxin. Ciba
Found Symp. 1994; 186:176-87.
Elsbach P and Weiss J. Prospects for use of recombinant BPI in
the treatment of gram-negative bacterial infections. Infect Agents
Dis. 1995; 4:104-9.
Engervall P; Granström E; Andersson M, and Björkholm M.
Monitoring of endotoxin, interleukin-6 and C-reactive protein
serum concentrations in neutropenic patients with fever. Eur J
Hemat. 1995; 54:226-234.
Faries P; Simon R; Martella A; Lee M, and Machiedo G.
Intestinal permeability correlates with severity of injury in trauma
patients. J Trauma Inj Infect Crit Care. 1998; 44(6):1031-6.
Freudenberg M; Meier-Dieter U; Staehelin T, and Galanos C.
Analysis of LPS released from Salmonella abortus equi in human
serum. Microb Pathogen. 1991; 10:93-104.
Froon A; Dentener M; Greve JW; Ramsay G, and Buurman W.
Lipopolysaccharide toxicity-regulating proteins in bacteremia. J
Infect Dis. 1995; 171:1250-7.
Fukui H; Brauner B; Bode Ch J, and Bode Ch. Plasma endotoxin
concentration in patients with alcoholic and non-alcoholic liver
disease: reevaluation with an improved chromogenic assay. J
Hepatol. 1991; 12:162-9.
Gardiner K; Halliday M; Barclay G; Milne L; Brown D; Stephens
S; Maxwell R, and Rowlands B. Significance of systemic endo-
toxaemia in inflammatory bowel disease. Gut. 1995; 36:897-901.
Gardlund B; Sjolin J; Nilsson A; Roll M; Wickerts C, and
Wretlind B. Plasma levels of cytokines in primary septic shock in
humans: correlation with disease severity. J Infect Dis. 1995;
172:296-301.
Gasche Y; Pittet D, and Suter P. Outcome and prognostic factors
in bacteremic sepsis. In: Sibbald WJ, Vincent JL (eds) Clinical
Trials for the Treatment of Sepesis, Springer-Verlag, Berlin, 1995,
35-51.
Geller D; Kispert P; Su G; Wang S; Di Silvio M; Tweardy D;
Billiar T, and Simmons R. Induction of hepatocyte lipopolysac-
charide binding protein in models of sepsis and the acute-phase
response. Arch Surg. 1993; 128:22-8.
Genco RJ. Periodontal disease and risk for myocardial infarction
and cardiovascular disease. CVR&R. 1998:34-40.
Giroir B; Quint P; Barton P; Kirsch E; Kitchen L; Goldstein B;
Nelson B; Wedel N; Carroll S, and Scannon P. Preliminary evalu-
ation of recombinant amino-terminal fragment of human bacteri-
cidal/permeability-increasing protein in children with severe
meningococcal sepsis. Lancet. 1997; 350:1439-43.
Glauser M; Zanetti G; Baumgartner J, and Cohen J. Septic shock:
pathogenesis. Lancet. 1991; 338:732-736.
Goldie A; Fearon K; Ross J; Barclay R; Jackson R; Grant I;
Ramsay G; Blyth A, and Howie C. Natural cytokine antagonists
and endogenous antiendotoxin core antibodies in sepsis syn-
drome. JAMA. 1995; 274(2):172-7.
Greatorex J and Thorne G. Humoral immune responses to shiga-
like toxins and Escherichia coli O157 lipopolysaccharide in
hemolytic-uremic syndrome patients and health subjects.
J Clin Microb. 1994; 32:1172-8.
Guidet B; Barakett V; Vassal T; Petit J, and Offenstadt G.
Endotoxemia and bacteremia in patients with sepsis syndrome in
the intensive care unit. Chest. 1994; 106(4):1194-1201.
Hackshaw K; Parker G, and Roberts J. Naloxone in septic shock.
Crit Care Med. 1990; 18(1):47-51.
Hansbrough J; Tenenhaus M; Wikstrom T; Braide M;
Mennekampff OH; Kiessig V, and Bjursten LM. Effects of recom-
binant bactericidal/permeability-increasing protein (rBPI
23
) on
neutrophil activity in burned rats. Journal of Trauma. 1990; 40(6):
886-893.
Hecht G. Bugs and barriers: enteric pathogens exploit yet another
epithelial function. News in Physiol Sci. 1995; 10:160-6.
Heseltine PNR; Berne TV; Luterman A; Carlson MR; Kim SS,
and White ML. Open label, pilot phase II trial of three dose levels
of recombinant bactericidal/permeability-increasing protein
(rBPI21) administered by continuous intravenous infusion to
patients with complicated intra-abdominal infections. Abstracts of
Page 30
25
the Interscience Conference on Antimicrobial Agents and
Chemotherapy. 1998; 38:603.
Hiki N; Berger D; Buttenschoen K; Boelke E; Seidelmann M;
Strecker W; Kinzl L, and Beger H. Endotoxemia and specific
antibody behavior against different endotoxins following multiple
injuries. J Trauma. 1995; 38(5):794-801.
Hoffman W and Natanson C. Endotoxin in septic shock. Anesth
Analg. 1993; 77(613-24).
Holzheimer R; Hirte J; Reith B; Engelhardt W; Horak K; Leppert
R; Aasen A; Capel P; Urbaschek R, and Karch H. Different
endoxtoxin release and IL-6 plasma levels after antibiotic admin-
istration in surgical intensive care patients. J Endotox Res. 1996;
3(3):261-7.
Huang K; Fishwild D; Wu H, and Dedrick R. Lipopolysaccaride-
induced e-selectin expression requires continuous presence of
LPS and is inhibited by bactericidal/permeability-increasing pro-
ten. Inflammation. 1995; 19(3):389-404.
Jackson J and Kropp H. Quantitative variations in beta-lactam
antibiotic released endotoxin from Pseudomonas Aeruginosa: in-
vivo relevance. Prog Clin Biolog Res. 1995; 392:235-51.
Jacob A; Goldberg P; Bloom N; Degenshein A, and Kozinn P.
Endotoxin and bacteria in portal blood. Gastroenterol. 1977;
72(6):1268-70.
Jagielo P; Quinn T; Qureshi N, and Schwartz D. Grain dust-
induced lung inflammation is reduced by Rhodobacter sphaeroides
diphosphoryl lipid A. Am J Physiol. 1998;274:L26-30.
Jones W II; Barber A; Minei J; Fahey T; Shires G T III, and
Shires G T. Differential pathophysiology of bacterial translocation
after thermal injury and sepsis. Ann Surg. 1991; 213(7):24-30.
Jones W II; Minei J; Barber A; Fahey T; Shires G T III, and
Shires G T. Splanchnic vasoconstriction and bacterial transloca-
tion after thermal injury. Am J Physiol. 1991;261:H1190-6.
Kaplan BS; Cleary TG, Obrig TG. Recent advances in under-
standing the pathogenesis of the hemolytic uremic syndromes.
Pediatric Nephrology. 1990; 4(3):276-83.
Karpman D; Connell H; Svensson M; Scheutz F; Alm P, and
Svanborg C. The role of lipopolysaccharide and shiga-like toxin
in a mouse model of Escherichia coli O157:H7 infection. J Infect
Dis. 1997; 175:611-20.
Kliegman RM; Walker WA, Yolken RH. Necrotizing enterocolitis:
Research agenda for a disease of unknown etiology and pathogen-
esis. Pediatric Research. 1993; 34(6):701-708.
Lambert L; Wong P; Hoppe P; and Scannon, P. Recombinant bac-
tericidal/permeability-increasing protein kills both gram-positive
and gram-negative bacteria. Abstracts of the Interscience
Conference on Antimicrobial Agents and Chemotherapy 34. 1994;
C6.
Lamy M; Deby-Dupont G, and Damas P. ARDS and sepsis:
resemblances and differences. In: Sibbald WJ, Vincent JL (eds)
Clinical Trials for the Treatment of Sepsis, Springer-Verlag,
Berlin, 1995, 35-51.
Langkamp-Henken B; Donovan T; Pate L; Doyle Maull C, and
Kudsk K . Increased intestinal permeability following blunt and
penetrating trauma. Crit Care Med. 1995; 23(4):660-4.
Lemaire L; Van Lanschot J; Stoutenbeek C; Van Deventer S;
Wells C, and Gouma D. Bacterial translocation in multiple organ
failure: cause or epiphenomenon still unproven. Br J Surg. 1997;
84:1340-50.
Lequier LL; Nikaidoh H; Leonard SR; Bokovoy JL; White ML;
Carroll SL; Scannon PJ, Giroir BP. Pre- and Post Operative
Endotoxemia in Children with Congenital Heart Failure. (manu-
script).
Liehr H; Grün M; Brunswig D, and Sautter Th. Endotoxaemia in
liver cirrhosis: treatment with polymyxin B. Lancet. 1975 Apr 5;
810-1.
Loesche W. Bacterial mediators in periodontal disease. Clin Infect
Dis. 1993; 16(Suppl 4):S203-10.
Ludwig K; Bitzan M; Zimmerman S; Kloth M; Ruder H, and
Muller-Wiefel D. Immune response to non-O157 vero toxin-pro-
ducting Escherichia coli in patients with hemolytic uremic syn-
drome. J Infect Dis. 1996; 174:1028-39.
Lyman M; Steward J, and Roantree R. Characterization of the vir-
ulence and antigenic structure of Salmonella Typhimurium strains
with lipopolysaccharide core defects. Infect Immun. 1976;
13(6):1539-42.
Marcus A and Hajjar D. Vascular transcellular signaling. J Lipid
Res. 1993; 34:2017-31.
Martinez-Pellus A; Merino P; Bru M; Conejero R; Seller G;
Munoz C; Fuentes T; Gonzalez G, and Alvarez B. Can selective
digestive decontamination avoid the endotoxemia and cytokine
activation promoted by cardioplumonary bypass? Crit Care Med.
1993; 21(11):1684-91.
Mathison J and Ulevitch R. The clearance, tissue distribution, and
cellular localization of intravenously injected lipopolysaccharide
in rabbits. J Immunol. 1979; 123(5):2133-43.
McCallum K; Schoenhals G; Laakso D; Clarke B, and Whitfield
C. A high-molecular-weight fraction of smooth lipopolysaccharide
in Klebsiella serotype O1:K20 contains a unique O-antigen epi-
tope and determines resistance to nonspecific serum killing. Infect
Immun. 1989; 57:3816-22.
McCloskey R; Straube R; Sanders C; Smith S, and Smith C.
Treatment of septic shock with human monoclonal antibody HA-
1A. Ann Intern Med. 1994; 121(1):1-5.
References
Page 31
26
References
McCuskey R; Urbaschek R, and Urbaschek B. The microcircula-
tion during endotoxemia. Cardiovasc Res. 1996; 32:752-763.
Meisner M. Procalcitonin. Berlin: Brahms-Diagnostica; 1996.
Milton DK; Amsel J; Reed CE; Enright PL; Brown LR;
Aughenbaugh GL, and Morey PR. Endotoxin exposure-response
in a fiberglass manufacturing facility. Am J Indust Med. 1996;
29(1):3-13.
Moore FA; Moore EE; Poffetti R; McAnena OJ; Peterson VM;
Abernathy CM, Parsons PE. Gut bacterial translocation via the
portal vein: a clinical perspective with major torso trauma. The
Journal of Trauma. 1991; 31(5):629-638.
National Committee for the Evaluation of Centoxin. The French
National Registry of HA-1A (Centoxin) in septic shock. A cohort
study of 600 patients. Arch Intern Med. 1994; 154:2484-91.
Ng K; Bhanumathy K; Ong G; Yong B; Parasakthi N; Koh M;
Siow C, and Bosco J. Endotoxin tests in patients with sepsis.
J Endotoxin Res. 1995; 2:387-393.
Nikaido H. Lipopolysaccaride in the taxonomy of enterobacteri-
aceae. Int J Syst Bacteriol. 1970; 20(4):383-406.
Nolan J. Endotoxin, reticuloendothelial function, and liver injury.
Hepatol. 1981; 1(5):458-65.
Odeh M. Endotoxin and tumor necrosis factor-a in the pathogene-
sis of hepatic encephalopathy.
J Clin Gastroenterol. 1994; 19(2):146-153.
Ognibene F. Pathogenesis and innovative treatment of septic
shock. Adv Int Med. 1997; 42:313-39.
Okubo S; Yasunaga K. Clinical and experimental studies on DIC
found in carcinoma; correlation between anti-cancer drug admin-
istration and endotoxemia. Gan No Rinsho - Japanese Journal of
Cancer Clinics. 1983; 29(7):803-806.
Opal SM. Pharmacokinetics of a recombinant amino terminal
fragment of bactericidal/permeability-increasing protein (rBPI21)
after liver surgery in rats and humans. Shock. 1998; 10(3):167-68.
Oudemans-van Straaten HM; Jansen PGM; Hoek FJ; van
Deventer SJH; Sturk A; Stoutenbeek CP; Tytgat GNJ; Wildevuur
CRH, Eysman L. Intestinal permeability, circulating endotoxin,
and postoperative systemic responses in cardiac surgery patients. J
of Cardiothoracic and Vascular Anesthesia. 1996; 10(2):187-194.
Pajkrt D; Doran J; Koster F; Lerch P; Arnet B; van der Poll T;
Wouter ten cate J, and van Deventer S. Anti-inflammatory effects
of reconstituted high-density lipoprotein during human endotox-
emia. J Exp Med. 1996; 184(1601-8).
Palmer R; Ferrige A, and Moncada S. Nitric oxide release
accounts for the biological activity of endothelium-derived relax-
ing factor. Nature. 1987; 327(11):524-6.
Parker T; Levine D; Chang J; Laxer J; Coffin C, and Rubin A.
Reconstituted high-density lipoprotein neutralizes gram-negative
bacterial lipopolysaccharides in human whole blood. Infect
Immun. 1995; 63(1):253-8.
Parrillo J. Pathogenetic mechanisms of septic shock. N Engl J
Med. 1993; 328(20):1471-7.
Patel P; Mendall M; Carrington D; Strachan D; Leatham E;
Molineaux N; Levy J; Blakeston C; Seymour C; Camm A, and
Northfield T. Association of Helicobacter pylori and Chlamydia
pneumoniae infections with coronary heart disease and cardiovas-
cular risk factors. BMJ. 1995; 311( ):711-4.
Perez-Garcia R; Anaya F; Garcia Vinuesa M; Albarracin C;
Tejedor A; Chisvert J, and Valderrabano F. Plasma tumor necrosis
factor alpha (TNF) and interleukin-6 (IL-6) in patients on
hemodialysis (HD). Kindey Internat. 1993;44:1495.
Porter S. Current status of clinical trials with anti-TNF. Chest.
1997; 112:339S-341S.
Prins J. Antibiotic induced release of endotoxin clinical data and
human studies. J Endotox Res. 1996; 3(3):269-73.
Rae D; Parter J; Neechy-Newman N; Sumar N; Bennett D, and
Hermon-Taylor J. Type 1 prophospholipase A2 propeptide in
acute lung injury. Lancet. 1994; 26(344):8935.
Rangel-Frausto M; Pittet D; Costigan M; Hwang T; Davis C, and
Wenzel R. The natural history of the systemic inflammatory
response syndrome (SIRS). JAMA. 1995; 273(2):117-23.
Reed L; Martin M; Manglano R; Newson B; Kocka F, and Barrett
J. Bacterial translocation following abdominal trauma in humans.
Circulatory Shock. 1994; 42:1-6.
Reinhart K; Wigand-Lohnert C; Grimminger F; Kaul M;
Withington S; Treacher D; Eckart J, and Willatts S. Assessment of
the safety and efficacy of the monoclonal anti-tumor necrosis fac-
tor antibody-fragment, MAK 195F, in patients with sepsis and
septic shock: a multicenter, randomized, placebo-controlled, dose-
ranging study. Crit Care Med. 1996; 24(5):733-42.
Remick D. Applied molecular biology of sepsis. J Crit Care.
1995; 10(4):198-212.
Rhodes A; Newman P, and Bennett E. Prognostic Markers in
Sepsis. Edt. JL Vincent. Berlin: Springer.
Riddington D; Venkatesh B; Boivin C; Bonser R; Elliott T;
Marshall T; Mountford P, and Bion J. Intestinal permeability, gas-
tric intramucosal pH, and systemic endotoxemia in patients under-
going cardiopulmonary bypass. JAMA. 1996; 275(13):1007-12.
Rietschel E; Holst O; Brade L; Muller-Loennies S; Mamat U;
Zahringer U, and Beckmann F. Bacterial endotoxin: chemical con-
stitution, biological recognition, host response, and immunologi-
cal detoxification. Curr Top Microbiol Immunol. 1996; 216:39-81.
Page 32
27
Stumacher R; Kovnat M, and McGabe W. Limitation of the use-
fulness of the limulus for endotoxin. N Engl J Med. 173;
208:1261-4.
Suffredini A; Fromm R; Parker M; Brenner M; Kovacs J; Wesley
R, and Parrillo J. The cardiovascular response of normal humans
to the administration of endotoxin. N Engl J Med. 1989;
321(5):280-7.
Sundaram S; King A, and Pereira B. Lipopolysaccharide-binding
protein and bactericidal/permeability-increasing factor during
hemodialysis: clinical determinants and role of different mem-
branes. J Am Soc Neph. 1996:8; 463-70.
Taggart D; Sundaram S; McCartney C; Bowman A; McIntyre H;
Courtney J, and Wheatley D. Endotoxemia, complement, and
white blood cell activation in cardiac surgery: a randomized trial
of laxatives and pulsatile perfusion. Ann Thorac Surg. 1994;
57:376-82.
Ulevitch R and Tobias P. Receptor-dependent mechanisms of cell
stimulation by bacterial endotoxin. Ann Rev Immonol. 1995;
13:437-457.
van Deventer S; ten Cate J, and Tytgat G. Intestinal endotoxemia
clinical significance. Gastroenterology. 1998; 94:825-31.
van Leeuwen P; Boermeester M; Houdijk A; Ferwerda Ch; Cuesta
M; Meyer S, and Wesdorp R. Clinical significance of transloca-
tion. Gut. 1994:S28-S34.
van Rooijen N. Are bacterial endotoxins involved in autoimmuni-
ty by CD5+ (LY-1+) B cells? Immunol Today. 1989;10:334-6.
Vane J; Änggard E, and Botting R. Regulatory functions of the
vascular endothelium. N Engl J Med. 1990; 323(1):27-36.
Verhoef J; Hustinx W; Frasa H, and Hoepelman A. Issues in the
adjunct therapy of severe sepsis. J Antimicrob Chemother. 1996;
38:167-182.
Warr T; Mohan Rao V, and Rapaport S. Disseminated intravascu-
lar coagulation in rabbits induced by administration of endotoxin
or tissue factor: Effect of anti-tissue factor antibodies and mea-
surement of plasma extrinsic pathway inhibitor activity. Blood.
1990; 75(7):1481-1489.
Watarida S; Mori A; Onoe M; Tabata R; Shiraishi S; Sugita T;
Nojima T; Nakajima Y, and Matsuno S. A clinical study on the
effects of pulsatile cardiopulmonary bypass on the blood endotox-
in levels. J Thorac Cardiovasc Surg. 1994;108:620-5.
Welbourn C and Young Y. Endotoxin, septic shock and acute lung
injury: neutrophils, macrophages and inflammatory mediators.
Br J Surg. 1992; 79:998-1003.
Wellmann W; Fink PC; Bener F, Schmidt FW. Endotoxaemia in
active Crohn's disease. Treatment with whole gut irriga and 5-
aminosalicyclic acid. Gut. 1986; 27(7):814-820.
Rintala E; Pulkki K; Mertsola J; Nevalainen T, and Nikoskelainen
J. Endotoxin, interleukin-6 and phospholipase-A2 as markers of
sepsis in patients with hemotological malignancies. Scand J Infect
Dis. 1995; 27(1):39-43.
Rocke D; Gaffin S; Wells M; Koen Y, and Brock-Utine J.
Endotoxemia associated with cardiopulmonary bypass. J Thorac
Cardiovasc Surg. 1987; 93:832-7.
Roumen R; Frieling J; van Tits J; van der Vliet J, and Goris R.
Endotoxemia after major vascular operations. J Vasc Surgery.
1993; 18:853-7.
Roumen R; Hendriks T; van der Ven-Jongekrijg J;
Nieuwenhuijzen G; Sauerwein R; van der Meer J, and Goris J.
Cytokine patterns in patients after major vascular surgery, hemor-
rhagic shock, and severe blunt trauma: relation with subsequent
adult respiratory distress syndrome and multiple organ failure.
Ann Surg. 1993; 218(6):769-76.
Ruiter D; Van Der Meulen J; Brouwer A; Hummel M; Mauw B;
Van Der Ploeg, and Wisse E. Uptake by liver cells of endotoxin
following its intravenous injection. Lab Invest. 1981; 45(1):38-45.
Saadia R; Schein M; MacFarlane C, and Boffard K. Gut barrier
function and the surgeon. Br J Surg. 1990; 77:487-92.
Scannon P. Sepsis Therapy: what's hot and what's not? Drug and
Market Development. 1997; 508:251-56.
Schafer C; Greiner B; Landig J; Feil E; Schutz T; Bode C, and
Bode C. Decreased endotoxin-binding capacity of whole blood in
patients with alcoholic liver disease. J Hepatol. 1997; 26:567-73.
Scheifele DW; Olsen EM, Pendray MR. Endotoxemia and throm-
bocytopenia during neonatal necrotizing enterocolitis. American J
of Clinical Pathology. 1985; 83(2):227-229.
Shenep J; Flynn P; Barrett F; Stidham G, and Westenkirchner D.
Serial quantitation of endotoxemia and bacteremia during therapy
for gram-negative bacterial sepsis. J Infect Dis. 1988; 157(3):565-8.
Siegel S; Evans M; Pollack M; Leone A; Kinney C; Tam S, and
Daddona P. Antibiotics enhance binding by human lipid A-reac-
tive monoclonal antibody HA-1A to smooth gram-negative bacte-
ria. Infect Immun. 1993; 61(2):512-9.
Smith JS; Scannon PJ;
et al
. Phase II trial of rBPI
21
(recombinant
bactericidal/permeability-increasing protein) in adults with hemor-
rhage due to trauma. Sixth Vienna Shock Forum. 1997; abs 45.
Spiewak R; Skorska C; Prazmo Z, and Dutkiewicz J. Bacterial
endotoxin associated with pollen as a potential factor aggravating
pollinosis. Ann Agric Environ Med. 1996; 3:63-6.
Steel D and Whitehead A. The major acute phase reactants: C-
reactive protein, serum amyloid P component and serum amyloid
A protein. Immunol Today. 1994; 15(2):81-8.
References
Page 33
28
Yoshida S; Matsui M; Shirouzu Y; Fujita H; Yamana H, Shirouzu
K. Effects of glutamine supplements and radiochemotherapy on
systemic immune and gut barrier funcion in patients with
advanced esophageal cancer. Annals of Surgery. 1998;
227(4):485-91.
Yu S; Nakashima N; Xu BH; Matsuda T; Izumihara A; Sunahara
N; Nakamura T; Tsukano M, and Matsuyama T. Pathological sig-
nificance of elevated soluble CD14 production in rheumatoid
arthritis: in the presence of soluble CD14, lipopolysaccharides at
low concentrations activate RA synovial fibroblasts. Rheumat
Internat. 1998; 17(6):237-43.
Wells C; Maddaus M; Erlandsen S, and Simmons R. Evidence for
the phagocytic transport of intestinal particles in dogs and rats.
Infect Immun. 1988; 56(1):278-82.
Wilkinson S; Moodie H; Stamatakis J; Kakkar V, and Williams R.
Endotoxaemia and renal failure in cirrhosis and obstructive jaun-
dice. Brit Med J. 1976; 2:1415-1418.
Wilmott R; Frenzke M; Kociela V, and Peng L. Plasma inter-
leukins and, tumor necrosis Factor-a, and lipopolysacharide
concentrations during pulmonary exacerbations of cystic fibrosis.
Pediat Pulmonol. 1994; 18:21-7.
Wilson M. Biological activities of lipopolysaccharides from oral
bacterial and their relevance to the pathogenesis of chronic peri-
odontitis. Sci Prog. 1995; 78(1):19-34.
References
Page 34
Gram- negative Bacteria/ Endotoxin
Tissue Factor
Clotting
Abnormalities
Shock, ARDS, DIC, Multiple Organ Failure, Death
Vasodilation
Capillary Leak
Fever
Metabolic Changes Hormonal Changes
Adhesion Molecules
Superoxide Radicals Lysosomal Enzymes
Neutrophil Accumulation
Coagulation System
Lipid Mediators
Nitric Oxide
Chemotaxis
Cytokines
TNF-
, IL-1, IL-6, IL-8, etc.
Complement System
Endothelial
Cells
Neutrophils
Monocytic Cells
Bradykinin
LBP
Figur
e 3: The Systemic Inflammatory Cascade
© 1998 XOMA Ltd.
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Randall
It raises the question, which came first as a problem for
psoriatics, the condom (rubber latex) or the acidic tomato? :) lol
Did not yar down under, onset after fiber glass and epoxy
work?
Those candy stripers could be usefull in more then one
scenario.
randall... cleaning up my P brain next.
Randall
After a heavy duty thanksgiving i can't think. :)
I see that dave posted the whole xoma pdf file. It
looks like xoma has a new website and those old
links no longer work.
So thanks for dave and of course daveW.
I think i'll try to whip uP something on P pathways.
More like inflammatory pathways in general.
These lectins and gliadins play a role in
mineral ratios and more. But today i'm hungover
from to much whipPed cream to soon after my desert. :)
And having to play sous chef for preparation and cooking of
the mashed potatoes, which means i was forced
to taste em to many times to get them perfect. :)
Those cavemen didn't have time to eat the high
glycemic foods once the mastodon needed to be
fileted. Plus they knew that they were
deadly night shade vegetables no doubt. :(
How else did we get the p DNA? Could
have been the apple pie in the garden
of paradise.
randall... still thankful anywhey