In accordance with the findings in previous studies [9, 36], this study revealed significantly lower plasma levels of TNF-α and IL-17 in DM patients with LTBI than non-LTBI counterparts, suggesting increased TB susceptibility through the decreasing phagocytic ability of macrophages, interference with granuloma formation [37] and inhibiting Mtb-specific memory responses [38]. This evidence concerns the gene IL17A and diabetes mellitus.