Background: Human immunodeficiency virus (HIV) infection leads to lower rates of hepatitis C virus (HCV) clearance after acute infection, higher HCV viremia, and accelerated progression of HCV-related fibrosis. The mechanisms underlying this acceleration of HCV progression by HIV are poorly understood, but HIV-induced dysfunction in the anti-HCV humoral immune response may play a role.
Methods: To define the effect of HIV coinfection on the anti-HCV antibody response, we measured anti-HCV envelope binding antibody titers, neutralizing antibody (nAb) titers, and nAb breadth of serum from HCV-infected subjects isolated longitudinally before and after incident HIV infection.
Results: A significant reduction in HCV envelope-specific binding antibody and nAb titers was detected in subjects with CD4(+) T-cell counts <350/mm(3) after HIV infection, and subjects with CD4(+) T-cell counts <200/mm(3) also showed a reduction in nAb breadth. Subjects who maintained CD4(+) T-cell counts ≥350/mm(3) displayed little to no decline in antibody levels.
Conclusions: Depletion of CD4(+) T cells by HIV infection results in a global decline in the anti-HCV envelope antibody response, including binding antibody titers, nAb titers, and nAb breadth.
Keywords: HCV; HIV; coinfection; neutralizing antibody.
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