Immune reconstitution inflammatory syndrome of tuberculosis among HIV-infected patients receiving antituberculous and antiretroviral therapy

Objective: To determine the frequency, risk factors and mortality rate of immune reconstitution inflammatory syndrome (IRIS) of tuberculosis (TB) in patients co-infected with HIV/TB and receiving antiretroviral therapy (ART). Methods: A retrospective study was conducted in Bamrasnaradura Infectious Diseases Institute and Ramathibodi Hospital, Thailand. Results: There were 167 patients with a mean age of 34.5 years. Median (IQR) CD4 cell counts was 36 (15-69) cells/mm³ and median (IQR) HIV RNA was 427,000 (189,000-750,000) copies/ml. ART was initiated at a median (IQR) duration of 2.2 (1.4-3.7) months after TB treatment. IRIS was identified in 21 (12.6%) patients. Patients with IRIS had a higher proportion of extrapulmonary TB than patients without IRIS (P < 0.001). By multivariate analysis, extrapulmonary TB was a risk factor for IRIS (odds ratio = 8.225, 95% confidence interval = 1.785-37.911, P = 0.007). Of 21 patients with IRIS, 15 patients developed IRIS within the first two months of ART. The mortality rate in patients with and without IRIS was not different (9.5% versus 2.1%, P = 0.119). Conclusions: The rate of TB IRIS is 13% in patients co-infected with HIV and TB. Extrapulmonary TB is a risk factor for IRIS. Closely monitored clinical care in the first few months of ART initiation and further interventional studies to minimize mortality of TB IRIS are needed.