Immunological alterations in tuberculosis associated immune reconstitution inflammatory syndrome in HIV infected patients

The tuberculosis associated immune reconstitution inflammatory syndrome (TB-IRIS) frequently complicates the course of HIV/AIDS and HIV-TB treatment and its immunological mechanisms are poorly understood. Here, we investigated T-cells frequencies, their secreted chemokines and cytokines. In this prospective case-control study, HIV/AIDS and HIV-TB patients during treatment with highly active antiretroviral treatment (HAART) and anti-TB treatment were followed for TB-IRIS development. Age, gender. and BMI-matched patients without IRIS constituted as "Controls" (non-IRIS). Activation and proliferation were assessed in CD4 and CD8 cell compartments. CCR4, CCR6 and T-reg cells were also analysed'in PBMCs. Cytokines (IL-2, IL-4, 1L-10, IFN-gamma and TGF-beta 1) and chemokines (IP-10, MCP-1, MIG and RANTES) were measured in culture supernatants. Of 560 enrolled HIV/AIDS patients, TB-IRIS developed in 50 (8.9%) patients (25-paradoxical and 25-unmasking) at a median interval of 35-days (IQR, 24-78). After ART therapy, CD8+ T-cell proportion decreased in both paradoxical and unmasking-TB-IRIS as compared to non-IRIS. Simultaneously, activation of CD4+ T-cells was observed in unmasking TB-IRIS only. Similarly, CD161+ T-cells, Th17-cells and inflammatory cytokines like IFN-gamma, IP-10 and MIG elevated in both TB-IRIS subgroups as compared to non-IRIS.In conclusion, during HAART treatment the dominance of pro-inflammatory cells-and cytokines in TB-IRIS patients favours the development of IRIS event. On the other hand, in non-IRIS patients relative increase of anti-inflammatory cells and cytokines prevents the development of IRIS event.