CATT polymorphism in MIF gene promoter is closely related to human pulmonary tuberculosis in a southwestern China population.

Macrophage migration inhibitory factor (MIF) is deemed as an immunoregulatory and proinflammatory cytokine related to the progression of tuberculosis. A CATT short tandem repeat (STR) polymorphism at position -794 in the MIF gene promoter region is associated with the susceptibility to tuberculosis (TB). To investigate whether macrophage MIF gene mif CATT variants are associated with susceptibility to retreatment cases of TB and drug-resistant TB prevalence, genotyping of MIF -794 CATT polymorphism and quantifying of serum MIF were performed to associate MIF-794 CATT polymorphism with new patients and retreatment cases. Significant increases in MIF -794 CATT genotypes 7/8 and allele CATT 8 were observed in TB patients. Significant differences in the genotypic frequencies of MIF -794 CATT (5/X + 6/X vs 7/7 + 7/8) were demonstrated upon comparing the total cases and the new cases of TB with the controls. Significant differences in the allelic frequencies of MIF -794 CATT (5 + 6 vs 7 + 8) were observed in the total cases and new cases of TB. No differences in the genotypic frequencies of the MIF -794 CATT (5/X + 6/X vs 7/7 + 7/8) were observed between the retreatment cases and the controls or between the new cases and retreatment cases. In conclusion, the MIF -794 CATT genotypes 7/8 and allele CATT 8 were highly associated with TB; no differences in the genotypic frequencies of the MIF -794 CATT (5/X + 6/X vs 7/7 + 7/8) were observed between the new cases and retreatment cases.