Immune activation caused by HIV mediates increased proliferation of CD4+ cells and makes these cells more vulnerable to infection and destruction by HIV, accelerating the progressive exhaustion of CD4+ cells.38,39 Our results showed that the expression of both CD38 and HLA-DR on CD8+ T-cells, but not on CD4+ T-cells, was significantly higher in TB+HIV+ patients than in the TB–HIV+ patients. Here, CD4 is linked to infection.