IL-18 gene polymorphism in patients with visceral leishmaniasis in East Azarbaijan, Iran.

Visceral leishmaniasis (VL) is a parasitic disease caused by Leishmania species. According to the important role of cellular immunity against VL, this study was directed to determine the frequency of -607A/C and -137G/C genotypes on promoter region of interleukin-18 gene. The study groups included 91 patients with confirmed history of VL, 106 healthy seronegative, and 79 healthy seropositive individuals. All three groups were analyzed by amplification refractory mutation system polymerase chain reaction (ARMS-PCR). The highest rate of -607/A, and -607/C alleles was observed in seronegative individuals (66/67 %) and in the patients (72/83 %). Allele frequency of -607/C is more than -607/A allele in all groups. In position of -137, frequency of -137/G allele in all groups was more than -137/C. Statistical analysis of distribution of genotypes, did not reveal any significant difference among groups. On the basis of the results, there was no significant association between VL and polymorphism of IL-18 promoter. The results of this study showed that IL-18 gene promoter polymorphisms at positions -607 and -137 are not associated with VL in East Azerbaijan, Iran.