Virological success of lopinavir/ritonavir salvage regimen is affected by an increasing number of lopinavir/ritonavir-related mutations.
Bongiovanni M., Bini T., Adorni F., Meraviglia P., Capetti A., Tordato F., Cicconi P., Chiesa E., Cordier L., Cargnel A., Landonio S., Rusconi S., d'Arminio Monforte A.
We evaluated the virological outcome of lopinavir/ritonavir (LPV/RTV) in 224 HIV-1-infected and protease inhibitor (PI)-experienced patients showing virological failure to a highly active antiretroviral therapy (HAART) regimen and followed up for at least 3 months. At baseline, the median level of plasma viraemia was 4.61 log10 copies/ml (range 3-6.48) and the median CD4 cell count was 219 cells/mm3 (range 1-836). During a median follow-up of 272 days (range 92-635), we observed an increase in the number of CD4 cells (P=0.02) and a dramatic decrease in plasma viraemia levels (P=0.0001), which became undetectable in 122 patients (54.5%). The closely related predictive factors were baseline plasma viraemia levels and the number of mutations known to reduce susceptibility to LPV/RTV. Thirty-one patients (13.8%) discontinued LPV/RTV during the follow-up, and one AIDS event and three deaths were recorded. Of the 134 patients (59.8%) who underwent a baseline genotype resistance test, 22 (16.4%) had > or = 6 mutations known to reduce LPV/RTV susceptibility; plasma viraemia became undetectable in 76 patients (56.7%), only five of whom harboured > or = 6 mutations at baseline (P=0.0001). The independent predictive factors related to virological success were plasma viraemia levels and the number of mutations reducing susceptibility to LPV/RTV at baseline; each additional log10 copies/ml of HIV RNA reduced the probability of virological success by 34.0% and each extra mutation by 14.5%.