CD8A and tuberculosis: Moreover, our findings of increased expression of Ki67 by CD8 T cells in TB, compared with IGRA– and IGRA+, provide further evidence of increased immune activation of CD4 and CD8 T cells in PWH with TB.7,14 Of note, elevated levels of activation on CD4 and CD8 T cells in our study was evident in people with active TB, but not IGRA+ individuals.