Strong CD4 Th1 responses to HIV and hepatitis C virus in HIV-infected long-term non-progressors co-infected with hepatitis C virus.

Objectives: To compare the T-cell responses to hepatitis C virus (HCV) and HIV in HIV-infected long-term non-progressors (LT-NP) and HIV-positive progressors co-infected with HCV and in HIV-negative HCV-infected patients.
Methods: Three groups were studied: 10 HCV/HIV-infected LT-NP, 26 HCV/HIV-infected progressors and 13 HCV-infected/HIV-negative patients. Virus-specific CD4 and CD8 T-cell responses in peripheral blood were assessed by interferon (IFN)-gamma Elispot assays using recombinant proteins (HIV-p24 and three HCV antigens) and 16 HIV or HCV HLA A3- and/or HLA A2-restricted cytotoxic T lymphocytes peptides. Statistical analysis was performed with non-parametric tests.
Results: In addition to high T helper 1 (Th1) cell frequencies directed against HIV-p24, LT-NP had significantly (P < 0.05) higher frequencies of Th1 cells against HCV than the two other groups. No difference was observed between HIV-infected progressors and HIV-negative controls. Furthermore, HCV-specific CD4 and CD8 T cells were correlated in LT-NP (P = 0.006).
Conclusion: Thus, independently of the HIV-related immune alterations, LT-NP of the HIV-infection might have an intrinsic capacity to develop strong Th1 cell responses to viruses, particularly HIV and HCV.