Mannose-binding lectin serum levels in patients with leprosy are influenced by age and MBL2 genotypes.

BACKGROUND: Mannose-binding lectin (MBL) activates the complement system promoting opsonophagocytosis, which could represent an advantage for Mycobacterium leprae, an intracellular pathogen. Therefore, a single nucleotide polymorphism (SNP) in the MBL2 gene associated with low levels of MBL could confer protection against the development of leprosy disease.

METHODS: In this study, we investigated SNPs of the MBL2 gene and MBL levels in 228 Brazilian leprosy patients and 232 controls.

RESULTS: There were no differences in the frequencies of variant genotypes and haplotypes of MBL2 between patients and controls, or between the different clinical forms of leprosy. In the group of patients with a genotype for high expression of MBL2, those aged>40 years had decreased MBL levels compared to patients aged ≤ 40 years (p = 0.037).

CONCLUSION: Our results demonstrate that age could influence the phenotype of MBL2, but no evidence was found for an association of MBL2 polymorphism with susceptibility to leprosy or its clinical forms.