To study the relationship between the CD4+ cell response after initiation of protease inhibitors and the occurrence of opportunistic infections and survival.Design:
Prospective observational cohort study.Methods:
HIV-1-seropositive subjects followed-up in HIV centres of Bordeaux University Hospital, Southwest France who were prescribed at least one available protease inhibitor between January and December 1996 were included in this analysis. A Cox model estimated the independent effect of baseline covariates and CD4+ cell response, considered as a time-dependent covariate, on the occurrence of new AIDS-defining opportunistic infection, new AIDS-defining events, new AIDS-defining opportunistic infection or death.Results:
A total of 556 HIV-positive patients were prescribed at least one protease inhibitor: 34% saquinavir, 52% indinavir, and 14% ritonavir. Median CD4+ cell count at baseline was 95 × 106/l and mean plasma HIV RNA was 5.0 log10 copies/ml. After a median follow-up of 230 days, 65 patients experienced a new episode of opportunistic infection, 79 patients experienced at least one AIDS-defining event, and 24 had died. On average, the increase in CD4+ cell count was 42 × 106/l (SD, 74) after a median of 49 days. In the multivariate analysis of opportunistic infection or death, each 50% higher CD4+ cell count at baseline was associated with a 23% reduction [95% confidence interval (CI), 14–30] of risk. Each 50% increase in CD4+ cell count during follow-up was associated with a 9% reduction (95% CI, 2–15) of risk, adjusted for the presence of AIDS prior to protease inhibitor therapy (hazard ratio, 3.76 versus absence of AIDS; P < 0.01) and haemoglobin level (hazard ratio, 0.48 if ≥ 11 g/dl versus <11 g/dl; P < 0.01).Conclusion:
Our results show, at least indirectly, how protease inhibitors might produce clinical stabilization. This result may be due to improved functionality of CD4+ cells in patients started on protease inhibitors.