Rajaa Ejghal and Meryem Lemrani
In this study we examine two polymorphic alleles -308 TNFα and +252 TNFβ, to determine their implication in the genetic predisposition to visceral leishmaniasis (VL) caused by Leishmania infantum in Moroccan children. We used PCR-RFLP method to genotype these two polymorphisms in 102 patients with VL, and 132 subjects with no history of Leishmania infection: 92 asymptomatic subjects with a positive skin test delayed type hypersensitivity (DTH+), and 40 healthy controls with a negative skin test delayed type hypersensitivity (DTH-). Statistical analysis showed no significant association between polymorphisms of TNFα when comparing with VL and DTH+ groups (p>0.05). The associations were detected between VL and DTH- groups for the heterozygote genotype (P=0.021), the recessive model: 1/2+2/2 (P=0.044) and the minor allele 2 (P=0.019). The resistance to VL was found to be under the recessive model 1/2+2/2 of tumor necrosis factors-β, when comparing with VL and DTH+ (odds ratios: 0.558, 95%; confidence interval: 0.316-0.987; P=0.044). Data provide that these preliminary results warrant further study with larger populations.