Content area
Full Text
Mol Biol Rep (2013) 40:40094014 DOI 10.1007/s11033-012-2479-x
Association of interleukin-18 gene variants with susceptibility to visceral leishmaniasis in Iranian population
Ali Moravej Manoochehr Rasouli
Sadaf Asaei Mehdi Kalani Yaser Mansoori
Received: 18 August 2012 / Accepted: 18 December 2012 / Published online: 27 December 2012 Springer Science+Business Media Dordrecht 2012
Abstract Host resistance to Leishmania infection is mediated by cellular immune responses leading to macrophage activation and parasite killing. Interleukin-18 (IL-18) known as interferon-c (IFN-c) inducing factor, stimulates IFN-c production by T cells. Taking into account the important role of IL-18 in the defense against visceral leishmaniasis (VL) and the known effect of IL-18 gene polymorphisms on its production, the aim of this study was to investigate the probable relationship between IL-18 gene polymorphisms and the susceptibility to VL. The study groups included 118 pediatric patients who suffered from VL and 156 non-relative healthy people as the controls from the same endemic area. IL-18 gene polymorphisms at the positions -656 G/T, -137 G/C and ?105A/C (codon 35/3) were analyzed by polymerase chain reaction-restricted fragment length polymorphism (PCR RFLP). The results showed that the frequency of T allele at the position -656 was signicantly higher in the controls, compared with that in the patients (P = 0.047), but it
couldnt tolerate Bonferroni correction. Regarding the IL-18 genotypes, there was no signicant difference between the patients and controls. Although the frequencies of ATG single haplotype and AGG/ATG double haplotype were signicantly higher in the controls (P = 0.043) and the patients (P = 0.044), respectively, the two P values couldnt tolerate Bonferroni correction. Furthermore, a strong linkage disequilibrium was observed among the -656, -137 and ?105 single nucleotide polymorphisms of IL-18 gene (all Ps \ 0.001). In conclusion, this study suggests that the inheritance of T allele at the position -656 may be considered as a genetic factor for resistance to VL.
Keywords Interleukin-18 Genetic polymorphisms
Visceral leishmaniasis Iran
Introduction
Visceral leishmaniasis (VL) is a systemic infectious disease caused by an intracellular protozoan belonging to Leishmania species. The majority of VL cases are caused by L. chagasi (in Latin America), L. donovani (in Africa, India, and south Asia), and L. infantum (in the Mediterranean littoral and the Middle East region) [1]. L. tropica is also reported as...