Impact of Hepatitis C Co-Infection on Response to Antiretroviral Treatment

The MONET study, comparing darunavir/ritonavir-based triple therapy and monotherapy, has foundhigher risk of failure in patients with positive HCV serology, but the effects of HCV co-infection on theefficacy of antiretroviral treatment have not been clearly established.A detailed MEDLINE search was conducted to identify cohort studies and clinical trials with publishedanalyses of the efficacy of antiretroviral treatment by HCV co-infection. A meta-analysis of the clinicaltrials was conducted, with the standardized endpoint of HIV RNA < 50 copies/ml at week 48 (intent totreat, time to loss of virologic response algorithm).Twelve cohort studies, seven clinical trials in antiretroviral-naive patients and three in pretreatedpatients were identified. In the clinical trials, 637/5,408 (12%) patients had HIV/HCV co-infection byHCV antibody tests; this percentage was in the lower range of the percentage of HIV/HCV co-infectedpatients reported in cohort studies in North America and Europe (median 37%, range 9-64%). In themeta-analysis of the clinical trials, the mean percentage of patients acheiving HIV RNA < 50 copies/mlat week 48 was 68.2% for HIV/HCV co-infected patients versus 80.4% for HIV mono-infected patients.The absolute difference in efficacy was 11.5% (95% CI: 7.7-15.3%; p < 0.001). However, a high proportionof endpoints in the time to loss of virologic response analysis were discontinuations of randomizedtreatment for adverse events or other reasons.The cause of the lower efficacy of antiretroviral treatment in HIV/HCV co-infected patients is unclear. Thelow percentage of HIV/HCV co-infected patients in this analysis, compared with published cohort studies,suggests that HCV co-infected patients are underrepresented in HIV clinical trials.