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).

A retrospective study was conducted in Bamrasnaradura Infectious Diseases Institute and Ramathibodi Hospital, Thailand.

There were 167 patients with a mean age of 34.5years. 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).

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.