Evaluation of IFN-gamma Polymorphism in Visceral Leishmaniasis

Background: Leishmaniasis is a tropical disease that is endemic in some areas of Iran, including East Azerbaijan. IFN-gamma is one of the cytokines that triggers cell-mediated immunity, thus initiating elimination of the infection. This case-control study was performed to investigate the association between the polymorphism of the IFN-gamma gene at the +874A/T locus and visceral leishmaniasis (VL). Methods: In this study conducted during 2012-2013, 267 participants were selected from individuals living in an endemic area of VL. Subjects were divided into three groups; 86 patients with VL, 82 seropositive individuals without any history of leishmaniasis, and 99 seronegative healthy controls. Genotyping of the IFN-gamma +874A/T polymorphism was carried out using an Amplification Refractory Mutation System-PCR (ARMS-PCR). Results: The frequency of the +874A allele in the patient group (75.5%) was higher than in the seropositive individuals (54%). The highest frequency of the +874T/T genotype was observed in seropositive individuals, while the patient group had the lowest frequency (34.1% vs. 24.5%). However, these differences were not significant. Conclusions: There was no significant association between IFN-gamma +874A/T polymorphism and VL.