CD38 and pulmonary tuberculosis: Furthermore, among the smear-positive pulmonary TB patients, the level of activation (HLA-DR, CD-38, Ki-67) markers from PPD specific double positive cytokine secreting CD4 + T cells during the six-month cohort was significantly reduced compared with second and baseline data (p-value = 0.0014, p-value = 0.042, p-value = 0.0129, p-value = 0.0002, p-value = 0.0001, respectively).