Association of MBL-2 gene polymorphisms with systemic lupus erythematosus: an updated meta-analysis and trial sequential analysis.

Objectives: Mannose-binding lectin (MBL), an essential innate immune molecule, enhances the opsonization process and activates the complement system. Genetic variations at the promoter and coding region of the MBL-2 gene have been associated with susceptibility to systemic lupus erythematosus (SLE); however, reports remained inconsistent. The present study performs a meta-analysis of published peer-reviewed articles to draw a definitive conclusion.

Materials And Methods: Published peer-reviewed articles on the association of MBL-2 gene polymorphisms and SLE were screened on various databases such as PubMed (Medline), ScienceDirect, and Google Scholar. A total of 23 eligible articles were included in the present study, comprising 3074 SLE patients and 3985 controls. Genotype and/or allele data for MBL-2 polymorphisms (A > B, A > C, A > D, A > O, Y > X and H > L) were extracted and analyzed by Comprehensive Meta-Analysis software (CMA V3.1).

Results: The overall analysis revealed a significant association of (A > O) polymorphism with a predisposition to SLE in allele contrast ( = 0.000; OR = 1.261), homozygous ( = 0.005; OR = 1.482), heterozygous ( = 0.004; OR = 1.247), dominant ( = 0.000; OR = 1.303) and recessive ( = 0.025; OR = 1.356) genetic comparison model. Similar results were also observed in the comparison of allele and the dominant genetic model of (A > B) polymorphism in overall (allele:  = 0.000, OR = 1.46, dominant:  = 0.001, OR = 1.31) and in the Asian cohorts (allele:  = 0.007, OR = 1.43, dominant:  = 0.008, OR = 1.32). Interestingly, (Y-221X) polymorphism exhibited protection against the development of SLE in heterozygous ( = 0.005, OR = 0.619) and dominant genetic comparison ( = 0.01, OR = 0.672) models.

Conclusions: variants (A > O and A > B) are associated with predisposition to SLE. Conversely, promoter polymorphism (Y-221X) offers protection against SLE development.