Association between TNF -308G/A polymorphism and susceptibility to pulmonary tuberculosis in the Lur population of Iran

ABSTRACT

Objective: To investigate whether tumor necrosis factor-a (TNFa) -238G/A and -308G/A polymorphisms are associated with susceptibility to pulmonary tuberculosis (TB) in the Lur ethnic population of Iran. Methods: TNF polymorphisms genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism method in 100 pulmonary TB patients and 100 healthy controls from the Lur population. Results: The allelic and genotypic frequencies of TNFa -238G/A polymorphism were not significantly different between the pulmonary TB patients and the healthy controls. However, the TNFa -308G/A polymorphism showed a significantly higher frequency of genotype GG in TB subjects compared to healthy controls (94% in the patients vs. 62% in the controls, P = 0.0001, odds ratio = 0.104, confidence interval = 0.028–0.382). Moreover, in the TNFa -308G/A polymorphism, a significantly higher frequency of G allele was measured in the patient group compared with the control group (97% in the patient group vs. 81% in the control group, P = 0.0001, odds ratio = 0.132, confidence interval = 0.038–0.462). Conclusions: Our findings suggest that TNFa -308G/A polymorphism may increase the susceptibility to pulmonary TB in the Lur population of Iran. Despite TNFa poly-morphisms and susceptibility to pulmonary TB, we suggest that more studies with larger sample size are needed in the future. Increasing our understanding of susceptibility risk factors may help to improve current preventive measures and treatment for TB.