Is the IL-10 -819 polymorphism associated with visceral leishmaniasis?

Previous investigations demonstrated that immune responses play critical roles in the defense against visceral leishmaniasis (VL). A key regulator of immune responses is the cytokine, IL-10 and polymorphisms within its promoter which could alter its expression. Thus, the aim of this study was to examine the correlation between polymorphism at the -819 position of the IL-10 gene and VL in a selected Iranian population. This cross-sectional study was performed on 100 patients with clinical presentation of VL and seropositive for the leishmania (group 1), 62 patients without clinical presentation but seropositive (group 2), and 128 healthy controls (group 3). The IL-10 -819 polymorphism was evaluated using the PCR-RFLP technique. The anti-leishmania antibody titration was assessed using an immunofluorescence assay. Our results showed that the polymorphism at IL-10 -819 (C/T) position was significantly associated with VL, and C/T genotype was significantly higher in VL patients when compared to groups 2 and 3 (p < 0.001). However, the results demonstrated that the C and T alleles were not associated with VL (p = 0.855). The data presented here confirm the results of previous reports that polymorphisms at the -819 position of the IL-10 gene can influence susceptibility to VL suggesting that the C/T genotype may be considered as a risk factor for the disease.