Abstract
BACKGROUND: Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is a clinical aggravation of TB symptoms observed among a fraction of HIV coinfected patients shortly after the start of antiretroviral therapy (ART). Of note, TB-IRIS is characterized by exacerbated inflammation and tissue damage that occurs in response to the elevated production of CD4(+) T cell-derived IFN-γ. Nevertheless, the possible participation of CD8(+) T cells in TB-IRIS development remains unclear. METHODS: We performed a comprehensive assessment of the composition of CD8(+) T cell memory subsets and their association with circulating inflammation-related molecules in TB-HIV coinfected patients initiating ART. RESULTS: We found that TB-IRIS individuals display higher frequencies of Antigen-experienced CD8(+) T cells during the onset of IRIS and that the levels of these cells positively correlate with baseline mycobacterial smear grade. TB-IRIS individuals exhibited higher frequencies of effector memory and lower percentages of naïve CD8(+) T cells than their Non-IRIS counterparts. In both TB-IRIS and Non-IRIS patients, ART commencement was associated with fewer significant correlations among memory CD8(+) T cells and cells from other immune compartments. Networks analysis revealed distinct patterns of correlation between each memory subset with inflammatory cytokines suggesting different dynamics of CD8(+) T cell memory subsets reconstitution. TB-IRIS patients displayed lower levels of memory cells positive for CXCR3 (a chemokine receptor that plays a role in trafficking activated CD8(+) T cells to the tissues) than Non-IRIS individuals before and after ART. Furthermore, we found that CXCR3(+) naïve CD8(+) T cells were inversely associated with the risk of TB-IRIS development. On the other hand, we noticed that the frequencies of CXCR3(+) effector CD8(+) T cells were positively associated with the probability of TB-IRIS development. CONCLUSION: Our data suggest that TB-IRIS individuals display a distinct profile of memory CD8(+) T cell subsets reconstitution after ART initiation. Moreover, our data point to a differential association between the frequencies of CXCR3(+) CD8(+) T cells and the risk of TB-IRIS development. Collectively, our findings lend insights into the potential role of memory CD8(+) T cells in TB-IRIS pathophysiology.