Background: The incidence and outcomes of paradoxical immune reconstitution inflammatory syndrome (IRIS) and unmasking tuberculosis-associated IRIS (TB-IRIS) after antiretroviral therapy (ART) initiation is not well defined.

Objective: To determine the cumulative incidence and outcomes of paradoxical and unmasking TB-IRIS after ART initiation

Materials and Methods: The authors performed a retrospective cohort study of HIV-infected patients starting ART at Siriraj Hospital between January 2010 and December 2013. The outcomes obtained were mortality, rate of hospitalization, the increment of CD4 cell count, and the proportion of virologic suppression six months and one year after ART initiation.

Results: Three hundred seventy HIV-infected patients were included, with a median CD4 cell count at baseline of 44 cells/mm³. Of the 120 patients who were diagnosed with TB before starting ART, 21 (17.5%) developed paradoxical TB-RIS at a median time of 24 days. Of the 250 patients who were not receiving TB treatment when ART was initiated, 18 (7.2%) experienced ARTassociated TB, with a median time of 47.5 days and 13 cases (5.2%) identified as unmasking TB-IRIS. No significant differences were found in the increments of the CD4 cell count and the proportions of virologic suppression at 6- and 12-month. Four patients who died did not develop TB-IRIS. Those with paradoxical TB-IRIS or ART-associated TB were hospitalized within six months after ART more frequently than those without TB-IRIS (33.3% and 33.3% versus 8.2%, respectively; p=0.001) and required more diagnostic procedures than those without TB-IRIS (42.9% and 55.6% versus 3.3%, respectively; p<0.001).

Conclusion: Patients with TB-IRIS were hospitalized and underwent a diagnostic procedure far more frequently than those without TB-IRIS, but none of the TB-IRIS patients died. ART should be provided early, and fear of any type of IRIS should not be a reason to defer ART in HIV-TB co-endemic areas.

Keywords: Tuberculosis-associated immune reconstitution inflammatory syndrome, TB-IRIS, HIV

Received 2 Jul 2019 | Revised 23 Jul 2019 | Accepted 24 Jul 2019