MTHFR polymorphisms (rs1801133) and systemic lupus erythematosus risk: A meta-analysis

BACKGROUND: The relationship between MTHFR (5, 10-methylene tetrahydrofolate reductase) gene polymorphisms and Systemic Lupus Erythematosus (SLE) has been wildly studied, but the results are still conflicting. Therefore, the purpose of this meta and pooled analysis was to identify the role of the MTHFR SNP (single nucleotide polymorphism, rs1801133) in SLE in a large sample of subjects and to assess the risk of SLE. METHODS: Data were collected from EMBASE, PubMed and China National Knowledge Infrastructure from inception to August, 2019. Summary odds ratio (OR) with 95% confidence interval (CI) was applied to assess the association. Subgroup and sensitivity analysis were performed to assess the potential sources of heterogeneity of the pooled estimation. RESULTS: We identified seven eligible studies involving 882 cases and 991 controls. MTHFR rs1801133 T carrier was significantly associated with increased risk of SLE when comparing to C allele [ORs were 1.766 (1.014–3.075) for T carrier vs CC, P = .04]. Furthermore, the results of the subgroup analysis by genotyping methods suggested that T allele significantly contributed to the risk of SLE for both by polymerase chain reaction-TaqMan (PCR-TaqMan) [10.111 (2.634–38.813) for TT vs CC, 3.467 (1.324–9.078) for CT vs CC and 3.744 (1.143–12.264) for TT vs C carrier]. Also the results of the subgroup analysis by ethnicity suggested that T allele significantly contributed to the risk of SLE for Asians [9.679 (4.444–21.082) for TT vs CC, 5.866 (3.021–11.389) for T carrier vs CC and 8.052 (3.861–16.795) for TT vs C carrier]. CONCLUSION: This cumulative meta-analysis showed that the MTHFR SNP (rs1801133) contributed to susceptibility of SLE. However, more multicentre well-designed case-control studies and larger sample sizes are exceedingly required to validate our findings in the future.