Interleukin 4-590T/C Polymorphism and Susceptibility to Leprosy

Background: Leprosy is a chronic infectious disease caused by Mycobacterium leprae. Cell-mediated (Th1) immune response and humoral (Th2) immune response play different roles in leprosy infection. Interleukin 4 (IL-4) is a typical Th2 cytokine. It is a critical mediator of the Th1/Th2 balance.Objective: The objective of this study is to investigate the association between IL-4 gene −590T/C polymorphism and the susceptibility to leprosy in a Chinese population. Methods: The IL-4 variant −590T/C was detected by polymerase chain reaction-restriction fragment length polymorphism in 432 leprosy cases and 465 age-matched healthy controls. Data were analyzed using the chi-square test. Results: Frequencies of the IL-4-590TC and CC genotypes and the −590C allele were significantly lower in patients with leprosy than in healthy controls (odds ratio [OR]=0.74, 95% confidence interval [CI] 0.55–0.99, p=0.044; OR=0.46, 95% CI 0.25–0.84, p=0.010; and OR=0.68, 95% CI 0.54–0.86, p=0.001, respectively). Conclusions: Our d...