Polymorphisms and Serum Level of Mannose-Binding Lectin: An Iranian Survey

Mannose-binding lectin (MBL) is a Ca+2 -dependent collagenous lectin, that is produced by liver and mediates innate immune responses by opsonization of pathogens. The serum level of MBL varies widely among healthy individuals, ranging from 0.05&g/ml (or lower) to over 5&g/ml, mainly depending on genetic variations. This study has examined promoter and exon 1 of mbl2 genotype among 117 Iranian healthy blood donors. MBL Single Nucleotide Polymorphisms (SNPs) were genotyped using polymerase chain reaction (PCR), and serum levels of MBL were quantified using a doubleantibody enzyme linked immunosorbent assay (ELISA). Results of this study showed that there are two promoter polymorphisms at -550 (H/L variants) and -221 (Y/X variants) positions, and three polymorphisms in exon 1 at codon 52 (D Allele), 54 (B Allele), and 57 (C Allele) in this population. B allele was significantly correlated with the lowest serum MBL level. Our results also showed that the most frequent genotype was HYA/LXA, and the genotype that associated with the highest serum level of MBL was HYA/HYA. The genotype that causes lowest MBL production in Iranian population was LYB/LXA. These results showed some differences compared to that of the other populations. To verfiy the originality of these differences we may need to extend the study to a larger samples of respective populations; meanwhile the importance of a new mutation, nucleotide 101 of MBL2 exon1, reported in the current study should be taken in considerations in terms of its possible pathobiological effects in following studies.