Influence of TNF and IL10 gene polymorphisms in the immunopathogenesis of leprosy in the south of Brazil

SummaryObjectiveTo determine whether cytokine polymorphisms are associated with leprosy and/or their subtypes in a Brazilian population.MethodsGenotyping using polymerase chain reaction with sequence-specific primers (PCR-SSP) was performed for: TNF−308/−238, IL2−330/+166, IL6−174, IFNG+874, TGFB1+869/+915, and IL10−592/−819/−1082 in 240 healthy controls and 167 patients with leprosy.ResultsFor TNF−308, a higher frequency of GG genotype (85.5% vs. 74.1% in healthy controls, p = 0.009), along with a decreased frequency of GA/AA genotypes was observed among leprosy patients as compared to the control group (14.5% vs. 25.9%, p = 0.009). The GG genotype was particularly higher in patients with tuberculoid (TT) and borderline (BB) leprosy (90.5% and 89.8%, respectively). Analysis of IL10 genotypes revealed a lower frequency of GCC/GCC haplotype in lepromatous leprosy (LL) patients (6.2%) in comparison to controls (15.4%).ConclusionIt is suggested that the G→A substitution at position −308 in the TNF promoter region plays an important role in leprosy patients.