Clinical progression, survival, and immune recovery during antiretroviral therapy in patients with HIV-1 and hepatitis C virus coinfection: the SwissHIV Cohort Study

Background Hepatitis C virus (HCV) infection is highly prevalent among HIV- 1-infected individuals, but its contribution to the morbidity and mortality of coinfected patients who receive potent antiretroviral therapy is contro versial. We used data from the ongoing Swiss HIV Cohort Study to analyse cl inical progression of HIV-1, and the virological and immunological response to potent antiretroviral therapy in HIV-1-infected patients with or withou t concurrent HCV infection. Methods We analysed prospective data on survival, clinical disease progress ion, suppression of HIV-1 replication, CD4-cell recovery, and frequency of changes in antiretroviral therapy according to HCV status in 3111 patients starting potent antiretroviral therapy. Results 1157 patients (37.2%) were coinfected with HCV, 1015 of whom (87.7% ) had a history of intravenous drug use. In multivariate Cox's regression, the probability of progression to a new AIDS-defining clinical event or to death was independently associated with HCV seropositivity (hazard ratio 1. 7 [95% CI 1.26-2.30]), and with active intravenous drug use (1.38 [1.02-1.8 8). Virological response to antiretroviral therapy and the probability of t reatment change were not associated with HCV serostatus. In contrast, HCV s eropositivity was associated with a smaller CD4-cell recovery (hazard ratio for a CD4-cell count increase of at least 50 cells/muL=0.79 [0.72-0.87]). Interpretation HCV and active intravenous drug use could be important facto rs in the morbidity and mortality among HIV-1-infected patients, possibly t hrough impaired CD4-cell recovery in HCV seropositive patients receiving po tent antiretroviral therapy. These findings are relevant for decisions abou t optimum timing for HCV treatment in the setting of HIV infection.