Preservation
of HCV-specific CD4 T-cell Responses in the Livers of HIV-HCV Coinfected Individuals Several
studies have shown that HIV coinfection
and low CD4 cell counts are associated
with more aggressive liver disease progression in patients with hepatitis
C. Some experts have hypothesized that HIV-related immunodeficiency impairs
HCV-specific immune responses. As
reported in the August 15, 2007 Journal of Infectious Diseases, researchers
assessed HCV-specific CD4 T-cell responses using interferon-gamma enzyme-linked
immunospot assays on peripheral blood mononuclear cells and expanded liver lymphocytes
from HCV monoinfected and HIV-HCV
coinfected subjects. Cell frequencies were determined using flow cytometry. Results
• HIV-HCV coinfection was associated
with decreased CD4 T-cell percentages in both peripheral blood (21% vs 48%; P
< 0.0001) and in the liver (15% vs 36%; P < 0.0001).
•
Coinfected subjects demonstrated reduced responsiveness of peripheral
blood CD4 T-cells to HCV antigens, compared with HCV monoinfected subjects (22%
vs 45%; P = 0.021).
• However,
intrahepatic HCV-specific responses were maintained in HIV-HCV coinfected compared
with HCV monoinfected subjects (38% vs 32%; P = 0.7).
•
The presence of HCV-specific responses was not related to the frequency
of CD4 T-cells in the liver (P = 0.4).
•
CD4 T-cell percentages in the circulating blood and in the liver were
correlated (R = 0.58; P < 0.0001).
•
Circulating percentages were inversely associated with liver
fibrosis stage among HIV-HCV coinfected subjects (P = 0.029).
•
Neither hepatic CD4 T-cell percentages nor HCV-specific interferon-gamma
responses in the liver or the peripheral blood predicted fibrosis stage.
Conclusion
In conclusion,
the authors wrote, "Despite decreases in peripheral blood HCV-specific CD4+
T cell responses and intrahepatic CD4+ T cell percentages, intrahepatic HCV-specific
CD4+ interferon-gamma responses were preserved in HCV/HIV coinfection." 7/20/07 Reference
C
Morishima, M Shuhart, C Yoshihara, and others. Preservation of Intrahepatic Hepatitis
C Virus (HCV)-Specific CD4+ T Cell Responses despite Global Loss of CD4+ T Cells
in HCV/HIV Coinfection. Journal of Infectious Diseases 196(4): 577-586.
August 15, 2007.
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