Toll-like receptor 4 (TLR4) polymorphisms in Iranian patients with visceral leishmaniasis

The role of Toll-like receptor (TLR) 4 in visceral leishmaniasis (VL), a disease caused by an obligate intracellular protozoan parasites belonging to the genus Leishmania, has been shown in the recent leishmaniasis experimental studies. As genetic host factors play an important role in the susceptibility and/or resistance to VL, the association between TLR4 gene mutations [A896G and C1196T single nucleotide polymorphisms (SNPs)] and VL was investigated. Genotyping of A896G (Asp299Gly) and C1196T (Thr399Ile) SNPs was performed in the patients with VL (N = 122) and ethnically matched controls (N = 155) using polymerase chain reaction-restriction fragment length polymorphism method. When VL patients and the controls were compared, no statistically significant differences were observed in A896G and C1196T alleles and genotypes (P > 0.05). The TLR4 A896G and C1196T were in moderate linkage disequilibrium in the controls and patients (r (2) = 0.497, 0.548 and D' = 0.705, 0.808, respectively), and haplotypes reconstructed from these SNPs were not significantly different between the aforementioned study groups. In conclusion, based on the results, TLR4 gene polymorphisms at the positions 896 and 1196 cannot be regarded as the major contributors to VL susceptibility among the Iranian population.