Coinfection of hepatitis C virus with human immunodeficiency virus and progression to AIDS. Italian Seroconversion Study.

To assess the influence of hepatitis C virus (HCV) on the natural history of human immunodeficiency virus (HIV) infection, a longitudinal study was conducted among 416 HIV-positive, AIDS-free persons infected through injecting drug use or homosexual or heterosexual activity and with known seroconversion dates. End points were diagnosis of AIDS and a CD4 cell count of < 100 x 10(6) cells/L. HCV antibodies were detected in 214 persons (51.4%). The crude relative hazard (RH) of progression to AIDS was 0.96 (95% confidence interval [CI], 0.53-1.76) for HCV-coinfected participants compared with those not coinfected. After adjustment for CD4 cell count, the RH was 0.97 (95% CI, 0.52-1.79). Similar RHs were found using a CD4 cell count of < 100 x 10(6) cells/L as the end point. The median CD4 cell loss was 4.83 x 10(6) cells/L per month among coinfected persons and 5.70 x 10(6) cells/L per month among the others. These results suggest that coinfection with HCV does not influence clinical and immunologic progression of HIV disease.