Interesting correlation between awakened bats with WNS and people treated for HIV

[Joanne Smith]

This month’s image comes from Carol U. Meteyer, Daniel Barber and Judith N. Mandl, “Pathology in euthermic bats with white nose syndrome suggests a natural manifestation of immune reconstitution inflammatory syndrome,” Virulence, 2012 Nov 15;3(7)

Abstract:  White nose syndrome, caused by Geomyces destructans, has killed more than 5 million cave hibernating bats in eastern North America. During hibernation, the lack of inflammatory cell recruitment at the site of fungal infection and erosion is consistent with a temperature-induced inhibition of immune cell trafficking. This immune suppression allows G. destructans to colonize and erode the skin of wings, ears and muzzle of bat hosts unchecked. Yet, paradoxically, within weeks of emergence from hibernation an intense neutrophilic inflammatory response to G. destructans is generated, causing severe pathology that can contribute to death. We hypothesize that the sudden reversal of immune suppression in bats upon the return to euthermia leads to a form of immune reconstitution inflammatory syndrome (IRIS). IRIS was first described in HIV-infected humans with low helper T lymphocyte counts and bacterial or fungal opportunistic infections. IRIS is a paradoxical and rapid worsening of symptoms in immune compromised humans upon restoration of immunity in the face of an ongoing infectious process. In humans with HIV, the restoration of adaptive immunity following suppression of HIV replication with anti-retroviral therapy (ART) can trigger severe immune-mediated tissue damage that can result in death. We propose that the sudden restoration of immune responses in bats infected with G. destructans results in an IRIS-like dysregulated immune response that causes the post-emergent pathology.

Caption:  Fig. 2 B and C — (C) One of nine Little Brown. Nine bats were found on the ground and unable to fly between April 4 and May 7, 2012. This bat was collected April 4, taken into rehabilitation, ate and drank, but died within 18 h of arrival. The wing was photographed outstretched over a light box and visible damage can be seen with dark areas of contraction and loss of elasticity. (D) Periodic acid Schiff stained section of wing membrane from the bat in Figure 2C. Severe neutrophilic inflammation and edema (bracket) in response to fungal hyphae (arrow).

 

 

Joanne Smith (Jo)
caver...@yahoo.com