Hepatitis Tests
Carrie
- include measurements of serologic markers that appear during course of
disease caused by hepatitis A virus (HAV), hepatitis B virus (HBV), or
hepatitis C virus (HCV), but is formerly known as non-A, non-B hepatitis
(NANB)
- lab methods used in the detection of specific antigens or antibodies
include the immunoassay (RIA) and enzyme immunoassay (EIA)
Hepatitis A
- self limiting disease that does not usually cause liver damage or a
chronic infectious state
- occurs as a result of oral ingestion of the virus and is characterized by
malaise, anorexia, fever, and nausea
- virus is present in feces, but diagnosis is based on serologic markers
(anti-HAV, IgM, IgG) identified in lab
- diagnosis is made if anti-HA antibodies can be demonstrated in the early
acute stage of the disease or if there is a high level of IgM anti-HA
compared to the level of IgG antibody to HA
- IgM antibodies appear in early states and IgG antibodies indicate past
infection and immunity to reinfection
Hepatitis B
- also known as Australian antigen
- more serious, prolonged disease that can result in liver damage and
chronic active hepatitis
- virus can be found in blood, feces, saliva, semen, sweat, urine, or any
body fluid of infected persons and can be transmitted by exposure to blood
products or parenteral contact (with needles) with articles contaminated
with material containing the virus
- diagnosis is made by identification of hepatitis B surface antigen (HBsAg)
circulating in blood before and during the acute early stage before enzyme
elevations or in the chronic carriers following acute illness
- first to become positive, and this is maintained until a response
(anti-HBs) is identified
- recovery and immuity to HBV as late as 6-10 months following active
infection is identified by detection of anti-HBs
- other tests are the hepatitis B antigen (HBeAg) that appears following
hepatitis B surface antigen (HBsAg) associated with core of virus during
acute infectious stage and can indicate a high degree of infectivity which
disappears when core antigen of the virus (HBcAg) is manufactured
- test for anti-HBe, and anti-HBc are antibody tests performed when other
evaluations have missed presence of HBsAg in the blood or before anti-HBs
titer rises
- delta hepatitis (HDV) coinfect with the hepatitis B virus and diagnosis is
made by detection of the antibodies (anti-D) in the blood
Hepatitis C
- parenterally acquired disease usually caused by blood transfusion but also
by IV drug abuse
- can lead to chronic hepatitis and cirrhosis of the liver
- test is done to detect the antibodies to HCV in the blood of those at risk
for the infection and transmission of the virus as a blood donor
- antibody formation can take as long as a year following exposure to the
virus
Carrie
Growing older is mandatory,
growing up is optional.
~Rich Yarnot~
Karl Fischer
<car...@vianet.on.ca> wrote:
> - lab methods used in the detection of specific antigens or antibodies
> include the immunoassay (RIA) and enzyme immunoassay (EIA)
RIA - radioimmunoassay; for detection of antibody-antigen interaction a
radioisotope (usually iodine125) is used as a tracer.
> Hepatitis B
> - also known as Australian antigen
Australian antigen is HBsAg (hepatitis B surface antigen)
The infectious particle is also known in older textbooks as the Dane particle.
> - virus can be found in blood, feces, saliva, semen, sweat, urine, or any
> body fluid of infected persons and can be transmitted by exposure to blood
> products or parenteral contact (with needles) with articles contaminated
> with material containing the virus
HBV is sexually transmitted as well as vertically transmitted (from mother
to newborne)
> Hepatitis C
> - parenterally acquired disease usually caused by blood transfusion but also
> by IV drug abuse
> - can lead to chronic hepatitis and cirrhosis of the liver
Leads to chronic infection in 85-90% of infected individuals.
Nicely done Carrie.
karl