Protease inhibitor therapy is associated with markedly prolonged time to relapse and improved survival in AIDS patients with cytomegalovirus retinitis

Abstract

Prior to the use of highly active antiretroviral therapy (HAART), cytomegalovirus retinitis (CMV-R) in AIDS patients was characterized by multiple relapses and decreased survival. Recent data suggest that CMV-R in patients treated with HAART may remain relapse-free for long periods. We performed a study of the effects of HIV protease inhibitors (PIs) on the incidence of relapse and time to death in AIDS patients with CMV-R treated with anti-CMV therapy. Medical records of all AIDS patients with CMV-R at Parkland Memorial Health and Hospital System treated with anti-CMV agents were reviewed for date of diagnosis of CMV-R, date of CMV-R relapse, type and duration of anti-CMV therapy, and duration of PI therapy. Relapse rates in subjects treated with PIs were compared with the relapse rates in those who were not treated with PIs. The primary endpoint was the time to relapse and death as determined by Kaplan-Meier analysis. Multivariate analysis was performed by Cox proportional hazard model. One hundred and nine cases of CMV-R were identified in 75 patients. Median follow-up time was 247 days (range 31-1818 days). There were 0.54 relapses per 1000 patient days in the group treated with PIs compared with 1.83 relapses per 1000 patient days in the non-PI treatment group (relative risk [RR]=0.29, P<0.01). Time to relapse was increased in the PI treatment group compared with the non-PI treatment group (endpoint not reached vs 182 days, P<0.001, log-rank). Similarly, the time to relapse or death was increased in the PI group compared with the non-PI group (543 days vs 103 days, P<0.001, log-rank). Multivariate analysis utilizing the Cox proportional hazards model demonstrated that only PI therapy but not anti-CMV therapy was associated with decreased risk of CMV-R relapse or death. Only 3 patients with an undetectable HIV viral load and one patient with a CD4 count >120 cells/µl had a relapse. We conclude that patients with CMV-R treated with HAART containing a PI have increased time to relapse and have prolonged survival.