Impact of the immune reconstitution inflammatory syndrome (IRIS) on mortality and morbidity in HIV-infected patients in Mexico

Objectives: To estimate the impact of immune reconstitution inflammatory syndrome (IRIS) on morbidity and mortality in patients starting highly-active antiretroviral therapy (HAART). Methods: A retrospective cohort study of HIV-positive patients starting HAART was conducted at a tertiary care referral center in Mexico City. We estimated the incidence of IRIS, hospitalizations and death rates during the first 2 years of HAART. The relative risk of death (RR) and hospitalization for patients with IRIS were adjusted for relevant covariates using regression methods. Results: During the 2-year follow-up period, 27% of patients developed IRIS (14 IRIS cases per 100 person-years). The relative risk of death among patients who developed IRIS was 3 times higher (95% confidence interval (CI) 1.19-7.65, p = 0.03). After adjusting for previous opportunistic infections we still observed a higher death rate among patients with IRIS (RR 2.3, 95% CI 0.9-5.9, p = 0.09). An effect modification of IRIS over mortality was observed by previous opportunistic infection. Conclusions: IRIS-associated mortality is strongly confounded by previous opportunistic infection. Patients with AIDS who eventually developed IRIS had the highest risk of death at the 2-year follow-up. (C) 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.