Response against Hepatitis B Virus Is Impaired in HIV-HBV Coinfected Individuals
T-cells targeting hepatitis B virus (HBV) are less effective in HIV positive people,
producing less cytokines and responding to fewer HBV proteins, according to a
study reported in the August
2009 Journal of Virology.|
Chang from the University of Melbourne and colleagues examined HBV-specific T-cell
responses in treatment-naive HIV-HBV coinfected
and HBV monoinfected Asian patients.
T-cells play a key role in both the control of HBV replication and the pathogenesis
of liver disease, the study authors noted as background, and HIV coinfection and
the presence of hepatitis B "e" antigen (HBeAg) may significantly alter
the natural history of chronic hepatitis B.
investigators looked at blood samples from 48 treatment-naive HIV-HBV coinfected
patients -- 24 of them HBeAg positive and 24 HBeAg negative -- and 39 HBV monoinfected
individuals. Blood was exposed to peptides representing the entire HBV genome.
The researchers measured tumor necrosis factor-alpha and gamma interferon cytokine
expression in CD8 T-cells using intracellular cytokine staining and flow cytometry.
was no difference in the overall magnitude of HBV-specific T-cell responses.|
quality of response, however, was significantly impaired in HIV-HBV coinfected
patients compared with HBV monoinfected individuals. |
coinfected patients, HBV-specific T-cells rarely produced more than 1 cytokine
and responded to fewer HBV proteins than those of monoinfected patients. |
the frequency and quality of HBV-specific T-cell responses were significantly
increased in association with higher CD4 T-cell counts. |
was no relationship between circulating HBV-specific T-cells and degree of liver
damage as measured by histological activity and fibrosis scores.|
T-cell responses were not significantly different in patients with HBeAg positive
versus HBeAg negative disease. |
on these findings, the investigators concluded, "The quality of the HBV-specific
T-cell response is impaired in the setting of HIV-1-HBV coinfection and is related
to the CD4 T-cell count."
of Melbourne, Melbourne, Australia; HIV-NAT and Chulalongkorn University, Bangkok,
Thailand; Victorian Infectious Diseases Reference Laboratory, Melbourne, Australia;
St. Vincent's Hospital, Melbourne, Australia; National Centre in HIV Epidemiology
and Clinical Research, University of New South Wales, Sydney, Australia; Infectious
Diseases Unit, Alfred Hospital, Melbourne, Australia; Monash University, Melbourne,
Australia; Royal Melbourne Hospital, Melbourne, Australia.
Chang, S Sirivichayakul, A Avihingsanon, and others. Impaired quality of the hepatitis
B virus (HBV)-specific T-cell response in human immunodeficiency virus type 1-HBV
coinfection. Journal of Virology 83(15): 7649-7658. August 2009. (Abstract).