Impact of TNF -308 G>A (rs1800629) gene polymorphism in modulation of leprosy risk: a reappraise meta-analysis of 14 case–control studies

PURPOSE Earlier studies have shown that tumor necrosis factor (TNF) -308 G>A (rs1800629) gene polymorphism is implicated in the susceptibility to leprosy, but results were inconsistent. METHODS A meta-analysis of 14 studies involving 3327 leprosy cases and 3203 controls was performed to appraise the association of TNF -308 G>A polymorphism with leprosy using MEDLINE (PUBMED), EMBASE, and Google Scholar web databases. RESULTS Overall, no significant association was observed in allelic (A vs. G: P=0.068; OR = 0.836, 95% CI = 0.689-1.013), homozygous (AA vs. GG: P=0.394; OR = 0.810, 95% CI = 0.499-1.315), heterozygous (GA vs. GG: P=0.059; OR = 0.780, 95% CI = 0.603-1.010), dominant (AA + GA vs. GG: P=0.067; OR = 0.797, 95% CI = 0.625-1.016), and recessive (AA vs. GG + GA: P=0.594; OR = 0.877, 95% CI = 0.542- 1.420) genetic models. Subgroup analysis showed no association in Asians. Whereas, reduced risk was found in allelic contrast (A vs. G: P=0.014; OR = 0.832, 95% CI = 0.718-0.963) and dominant models (AA + GA vs. GG: P=0.004; OR = 0.790, 95% CI = 0.673-0.928) of the mixed population. CONCLUSIONS TNF -308 G>A polymorphism is not associated with leprosy risk in the overall population. However, subgroup analysis demonstrated protective effect of the said polymorphism in leprosy risk in the Latin American population, but showed no association in the Asians.