Paradoxical immune reconstitution inflammatory syndrome in HIV-infected patients treated with combination antiretroviral therapy after AIDS-defining opportunistic infection.

BACKGROUND: The incidence of immune reconstitution inflammatory syndrome (IRIS) when antiretroviral therapy (ART) is initiated after an AIDS-defining opportunistic infection (OI) is uncertain and understudied for the most common OIs.

METHODS: We examined patients in the University of Washington Human Immunodeficiency Virus Cohort initiating potent ART subsequent to an AIDS-defining OI. IRIS was determined through retrospective medical record review and adjudication using a standardized data collection process and clinical case definition. We compared demographic and clinical characteristics, and immunologic changes in patients with and without IRIS.

RESULTS: Among 196 patients with 260 OIs, 21 (11%; 95% confidence interval, 7%-16%) developed paradoxical IRIS in the first year on ART. The 3 most common OIs among study patients were Pneumocystis pneumonia (PCP, 28%), Candida esophagitis (23%), and Kaposi sarcoma (KS, 16%). Cumulative 1-year incidence of IRIS was 29% (12/41) for KS, 16% (4/25) for tuberculosis, 14% (1/7) for Cryptococcus, 10% (1/10) for Mycobacterium avium complex, and 4% (3/72) for PCP. Morbidity and mortality were highest in those with visceral KS-IRIS compared with other types of IRIS (100% [6/6] vs 7% [1/15], P < .01). Patients with mucocutaneous KS and tuberculosis-IRIS experienced greater median increase in CD4(+) cell count during the first 6 months of ART compared with those without IRIS (+158 vs +53 cells/μL, P = .04, mucocutaneous KS; +261 vs +113, P = .04, tuberculosis).

CONCLUSIONS: Cumulative incidence and features of IRIS varied depending on the OI. IRIS occurred in >10% of patients with KS, tuberculosis, or Cryptococcus. Visceral KS-IRIS led to considerable morbidity and mortality.