Rationale: HIV-tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is an immunopathological reaction to mycobacterial antigens induced by antiretroviral therapy. Prednisone reduces morbidity in TB-IRIS, but the mechanisms are unclear. Objectives: To determine the effect of prednisone on the inflammatory response in TB-IRIS (antigen-specific effector T cells, cytokines, and chemokines). Methods: Blood was taken from participants in a randomized placebocontrolled trial of prednisone for TB-IRIS, at 0, 2, and 4 weeks. Participants received prednisone at a dosage of 1.5 mg/kg/day for 2 weeks followed by 0.75 mg/kg/day for 2 weeks, or placebo at identical dosages. Measurements and Main Results: Analyses included IFN-g enzymelinked immunospot (ELISPOT), reverse transcription-polymerase chain reaction on peripheral blood mononuclear cells after restimulation with heat-killed Mycobacterium tuberculosis, Luminex multiplex cytokine analysis of corresponding tissue culture supernatants, and Luminex multiplex cytokine analysis of serum. Fifty-eight participants with TB-IRIS (31 receiving prednisone, 27 receiving placebo) were included. In serum, significant decreases in IL-6, IL-10, IL-12 p40, tumor necrosis factor-a, IFN-g, and IFN-g-induced protein-10 concentrations during prednisone, but not placebo, treatment were observed. No differences in ELISPOT responses comparing prednisone and placebo groups were shown in response to ESAT-6 (early secreted antigen target-6), Acr1, Acr2, 38-kD antigen, or heat-killed H37Rv M. tuberculosis. Purified protein derivative ELISPOT responses increased over 4 weeks in the prednisone group and decreased in the placebo group (P ¼ 0.007). Conclusions: The beneficial effects of prednisone in TB-IRIS appear to be mediated via suppression of predominantly proinflammatory cytokine responses of innate immune origin, not via a reduction of the numbers of antigen-specific T cells in peripheral blood.

Vitamin D deficiency is common in human immunodeficiency virus–tuberculosis coinfected patients in Cape Town. Those who develop tuberculosis-immune reconstitution inflammatory syndrome have a further reduction in circulating 25-hydroxyvitamin D levels 2 weeks into combined antiretroviral therapy with a concomitant increase in inflammatory cytokines and chemokines.