Polymorphisms of the mannose binding lectin (MBL2) gene are related to protein plasma levels but not with visceral leishmaniasis in a northeastern brazilian population

Mannose-binding lectin (MBL) is a lectin complement protein encoded by the MBL2 gene that has an important role in the control of infections caused by intracellular pathogens. However, there is no consensus about the effect of MBL2 polymorphism and MBL levels in leishmaniasis infections. We investigated the implications of MBL2 gene variants as well as MBL serum levels and occurrence of visceral leishmaniosis (VL) caused by Leishmania chagasi. A case-control analytic study was performed on 161 patients with VL and 161 healthy individuals in a northeast region of Brazil. The alleles of exon 1 (MBL2*A, MBL2*B, MBL2*C and MBL2*D) and promoter region (-550L/H, -221Y/X and +4P/Q) were identified by automatic sequencing and the MBL serum levels were determined using an ELISA kit. MBL serum levels were similar in VL patients compared to the healthy controls. Also, allelic, genotype and haplotype frequencies of variants in exon 1 and promoter region did not significantly differ between case and control groups. Overall, our data show that MBL2 polymorphisms within the structural gene as well as the promoter region influence functional MBL serum levels but are not associated with susceptibility to L. chagasi infection in this population. We observed a lack of consensus regarding the association of MBL 2 polymorphisms with leishmaniasis worldwide, indicating that the influence of genetic variations can differ in different populations and with differences in parasite/vector relationship.