Clinical outcome and predictive factors of failure of highly active antiretroviral therapy in antiretroviral-experienced patients in advanced stages of HIV-1 infection

Objective: To verify the effectiveness of highly active antiretroviral therapy (HAART) and to identify any factors predictive of clinical outcome in a clinical setting. Design: Observational study. Methods: Treatment failure (i.e., the occurrence of new or recurrent AIDS-defining events, death or any definitive discontinuation) and the course of CD4+ cell counts and HIV RNA copies were evaluated in 250 heavily pretreated HIV-infected patients starting HAART [153 with indinavir (IDV), 55 with ritonavir (RTV), 43 with saquinavir (SQV)]. Univariate and multivariate analyses were performed to identify predictors of worse outcome. Results: During a median follow-up of 8 months, 75 patients (30%) had treatment failure because of the occurrence of an AIDS-defining event or death (n = 24), inefficacy (n = 24), or severe intolerance (n = 27). Twenty new and six recurrent AIDS-defining events, and nine deaths occurred (six out of 20 AIDS-defining events and two out of nine deaths within 1 month of treatment). CD4+ counts were above 200 x 10(6)/l at AIDS diagnosis in only two patients. None of the SQV patients, 12 (7.8%) of the IDV patients, and 15 (27.3%) of the RTV-treated patients were considered non-compliant. The SQV-containing regimens independently correlated with treatment failure (relative risk, 2.46; 95% confidence interval, 1.20-5.03; versus IDV). Low compliance partially determined outcome in RTV-treated patients; both severe immunodepression and AIDS at baseline were predictive of treatment failure. There was a 10-fold increase in CD4+ cell counts in the patients treated with IDV and RTV; the best virological outcome occurred in IDV-treated patients, with 68.4% of patients showing undetectable HIV RNA copies after 6 months. Conclusions: HAART was effective in 70% of patients; low compliance and previous AIDS diagnosis represented predictive factors of therapy failure.