Effect of hepatitis G virus infection on progression of HIV infection in patients with hemophilia

Background: Infection with hepatitis G virus (HGV), also known as GB virus C, is prevalent but is not known to be associated with any chronic disease. Infection with HGV may affect the risk for AIDS in HIV-infected persons. Objective: To compare AIDS-free survival in patients with and those without HGV infection during 16 years of followup after HIV seroconversion. Design: Subanalysis of a prospective cohort study. Setting: Comprehensive hemophilia treatment centers in the United States and Europe. Patients: 131 patients with hemophilia who became HIV-positive between 1978 and 1985. Measurements: Age, CCR5 genotype, HIV and HCV viral loads, CD4(+) and CD8(+) lymphocyte counts, and 12-year AIDS-free survival by HGV positivity (viremia [RNA] or anti-E2 antibodies). Results: Compared with HGV-negative patients, the 60 HGV-positive patients (46%), including 22 who were positive for HGV RNA, had higher CD4(+) lymphocyte counts (difference, 211 cells/mm(3) [95% CI, 88 to 333 cells/mm(3)]) and 12-year AIDS-free survival rates (68% compared with 40%; rate difference, 1.9 per 100 person-years [Cl, -0.3 to 4.2 per 100 person-years]), despite similar ages and HIV viral loads. In multivariate proportional hazards models, risk for AIDS was 40% lower for HCV-positive patients independent of age, HIV and HCV viral loads, CD4(+) and CD8(+) lymphocyte counts, and CCR5 genotype. Conclusions: Patients with past or current HGV infection have higher CD4(+) lymphocyte counts and better AIDS-free survival rates. The mechanism of this association is unknown.