CD8+ cell responses to Hepatitis C Virus (HCV) in the liver of persons with HCV-HIV coinfection versus HCV monoinfection

Abstract

Objective. Cellular immune responses are difficult to detect in the peripheral blood of persons with chronic hepatitis C virus (HCV) infection. We sought to determine whether T cell responses were present in the liver of patients with human immunodeficiency virus (HIV) and HCV coinfection. Methods. T cells were expanded from liver-biopsy samples from 10 patients coinfected with HIV and HCV (median CD4+ cell count, 456 cells/mm3) and 8 patients infected with HCV alone. CD8+ cell responses were detected by use of a modified enzyme-linked immunospot (ELISpot) assay with recombinant vaccinia virus, and CD4+ cell responses were detected by use of ELISpot with recombinant HCV proteins core, nonstructural (NS) 3, and NS5. Results. Intrahepatic CD8+ cell responses to HCV were detected in 7 of 10 patients coinfected with HCV and HIV (median frequency, 638 spot-forming cells [sfc]/1 × 106 cells) and were similar to those observed in patients singly infected with HCV (7/8; median, 647 sfc/1 × 10 6 cells). Intrahepatic HCV-specific CD4+ cell responses were also comparable in both groups and correlated with the intrahepatic CD8+ cell responses (r = 0.59; P = .03). Conclusion. HCV-specific CD8+ cell responses are present in the liver of persons with chronic HCV infection even when they are coinfected with HIV; these correlate with intrahepatic HCV-specific CD4- cell responses.