TNF and tuberculosis: Since TNF-α is important for walling off infections and preventing dissemination by granuloma formation, low levels of TNF-α, as seen in our PTB patients, could impair the containment of the M. tuberculosis bacilli, leading to difficult resolution of active disease, dampening the efficiency of anti-TB treatment and increasing the reactivation risk, as shown in rheumatoid arthritis patients who were undergoing anti-TNF-α therapy [52, 53].