Yellow Fever Research Today is a free monthly online journal that collates and summarizes the latest research about Yellow Fever, including details on immunization, vaccines, symptoms, transmission.

Immunohistochemical examination of the role of Fas ligand and lymphocytes in the pathogenesis of human liver yellow fever.

Quaresma JA, Barros VL, Fernandes ER, Pagliari C, Guedes F, da Costa Vasconcelos PF, de Andrade Junior HF, Duarte MI

Núcleo de Medicina Tropical, Universidade Federal do Pará, Av. Generalissimo Deodoro 92, 66055-240, Belém, Pará, Brazil. juarez@ufpa.br

Yellow fever is an infectious, non-contagious disease caused by an RNA virus of the family Flaviviridae, which is transmitted to man by the bite of hematophagous mosquitoes. Infection with the yellow fever virus can progress with lesions in the heart, kidneys, central nervous system, and liver. In the liver, the histopathological picture is characterized by necrosis, steatosis and hepatocyte apoptosis, with a preferential midzone distribution. In the present study, liver samples from fatal patients with yellow fever were analyzed. The histopathological pattern was characterized by steatosis, lytic necrosis and hepatocyte apoptosis associated with a moderate mononuclear inflammatory infiltrate. The inflammatory component mainly consisted of CD4+ T lymphocytes, followed by CD8+ T lymphocytes, which showed a preferential portal and midzone distribution. Immunoreactivity to Fas ligand was mainly observed in hepatocytes of the midzone region. Based on these findings, we conclude that lymphocytes play an important role in the genesis of hepatic lesions in severe yellow fever, inducing hepatocyte apoptosis through the binding to Fas receptors. However, further studies are necessary to investigate the participation of other immune factors and to quantify the role of the cytotoxic cellular response in the lesion evolution during the course of disease in the liver.

Published 14 February 2006 in Virus Res, 116(1): 91-7.
Full-text of this article is available online (may require subscription).

© 2005-2008 Yellow Fever Research Today. All Rights Reserved.