Comparative Immunovirological and Clinical Responses to Antiretroviral Therapy Between HIV-1 Group O and HIV-1 Group M Infected Patients

International audienceBACKGROUND:Genetic divergence of HIV-1/O relative to HIV-1/M impacts virological monitoring and drug susceptibility, but little is known about impact on therapeutic outcomes. We aimed to determine if responses to standardized cART were similar between groups despite strain divergence.METHODS:We performed an open non-randomized study comparing the immunological, virological and clinical responses to cART based on 2NRTIs+1PI/r, in naive and paired HIV-1/O- versus HIV-1/M-infected patients (ratio 1:2), matched on sex, age, CD4 count, hemoglobin level, and HBsAg status. The primary endpoint was the proportion of patients with undetectable plasma viral load (pVL, threshold 60 cp/mL) at W48. Secondary endpoints were the proportion of patients with undetectable pVL at W24 and W96 and CD4 evolution between baseline and W24, W48 and W96.RESULTS:47 HIV-1/O and 94 HIV-1/M patients were included. Mean pVL at baseline was significantly lower by 1 log for HIV-1/O versus HIV-1/M patients. At W48, no significant difference was observed between populations with undetectable pVL in 80.9% of HIV-1/O versus 75.5% of HIV-1/M patients. Differences at W24 and W96 were not significant. A difference in CD4 gain was observed in favor of HIV-1/M at W48 and W96, but this was not significant when adjusted on both matched criteria and pVL at baseline.CONCLUSIONS:Our data demonstrate similar immuno-virological and clinical response between HIV-1/O and HIV-1/M patients, suggesting that genetic divergence does not impact therapeutic outcomes. They also reveal significantly lower baseline replication for HIV-1/O variants, suggesting specific virological properties and physiopathology that now need to be addressed