In a multivariate analysis, Cox regression showed that only the baseline sputum smear microscopy grade was independently associated with prolonged smear positivity in MDR-TB patients at the end of 12 weeks following anti-TB initiation (B = −0.405; SE = 0.159; Wald = 6.464; Exp (B) = 0.667; p = 0.011) after adjusting for HIV status, CD4+ T-cell count, and age. This evidence concerns the gene CD4 and tuberculosis.