Association between the IFNG +874A/T gene polymorphism and leprosy resistance: A meta-analysis

•IFN-γ cytokine plays an important role in the immune response.•We investigated a possible association of +874T IFNG to leprosy.•Meta-analysis was performed in leprosy patients and controls subjects.•IFNG +874T allele may be protected from developing leprosy.•IFN-γ polymorphisms may be related to a higher cellular immune response in leprosy. Previous studies identified the variant IFNG +874A/T (rs2430561) in the first intron of the gene in association with mycobacterial infection, especially tuberculosis and leprosy. The aim of this investigation was to analyze the protective role of the T allele in relation to leprosy using a meta-analysis evaluation. Thus, 1573 patients and 1914 controls were included and analyzed in fixed effects model. The T allele is associated with a protective effect for leprosy under the dominant model (pooled OR=0.83, 95% CI=0.72–0.96, p=0.011) suggesting that carriers of the IFNG +874T allele may be protected from developing leprosy. The T allele has been suggested to correlate with high interferon-γ levels. A phenotype with high IFN-γ producing and an increased inflammatory profile may account for these findings. This meta-analysis suggests that IFNG +874T allele is associated with leprosy resistance.