Background The mannose-binding lectin protein (MBL) is a multimeric molecule with a structure that is the analogue to the C1q protein. Deficient and low MBL concentrations in serum are due to the presence of mutations in the structural or promoter region
Objectives To investigate the role of alleles and haplotypes of MBL2 gene in the clinical expression of systemic lupus erythematosus (SLE) and its association with infections in Mexican-mestizo patients.
Methods An observational, cross-sectional, retrospective study. We included 74 SLE patients and 75 matched controls. All ≥16 years-old who met at least four 1982 or revised 1997 ACR criteria for SLE were included. The association of MBL locus haplotypes with disease activity and past history of infection was studied in those patients. Allele and haplotype determinations in the promoter and structural regions of the MBL2 gene were performed from genomic DNA isolated peripheral blood. Probes were sent to Invitrogen (Carlsbad, California) for synthesis. The disease activity was determined by MEX-SLEDAI. Infections were categorized arbitrarily if patients had ≥4 events. The associations between the codons, clinical activity, and having ≥4 infection events were by odds ratio.
Results There were 13/73 (17.8%) SLE patients with ≥4 infections. The presence of homozygous C/C codon 57 was observed to be greater risk for SLE activity and present more than 4 infections. The significance of heterozygous HYLX promoter was observed only for the presence of infection. Table 1.
Conclusions MBL2 gene polymorphisms of the homozygous C/C in codon 57 of the structural region and heterozygous HYLX of the promoter region are associated with increased risk of a higher number of infections. Also, we observed that homozygous C/C in codon 57 was asociated to a higher MEX-SLEDAI.
Disclosure of Interest None declared