Association between metformin therapeutic efficacy and SLC47A1 polymorphism in systemic lupus erythematosus / 中华风湿病学杂志

ABSTRACT

Objective:To evaluate the association between the efficacy and safety of metformin and the influence of variants in SLC47A1 rs2289669 G>A polymorphism in the treatment of systemic lupus erythematosus (SLE).Methods:A multicenter, randomized, double-blind, placebo-controlled trial was conducted. Patients were consented at enrollment for blood donation for genotyping, and their peripheral blood were used to detect the distribution frequency of SLC47A1 mutations. The major or mild/moderate flares defined by modified safety lupus erythematosus national assessment (SELENA)-systemic lupus erythematosus disease activity index (SLEDAI) Flare Index (SFI) and adverse events were recorded at 12 months of follow-up. The correlation between efficacy/safety and genotype was analyzed. Student's t test and χ2 test was used to assess the continuous variables and categorical variables. Results:Between May 24, 2016, and Dec 13, 2017, a total of 31 patients in the metformin group and 35 in the placebo group were detected. There were no statistical significant differences in the clinical manifestations, SELENA-SLEDAI scores, and therapy of the participants at baseline. There was no significant difference in the frequency of AA genotype, GA genotype, and GG genotype of SLC47A1 rs2289669 distribution between the metformin group and the placebo group. In the metformin group, patients who flared had a lower frequency of A alleles than those non-flared [25%(4/16) vs 61%(28/46), χ2=6.116, P=0.019 8]; the flare rate was significantly lower in patients with AA genotype than in GG genotype [0%(0/8) vs 57%(4/7), χ2=6.234, P=0.012 5]. The infection rate was lower in the metformin group than that in the placebo group [38%(12/31) vs 69%(24/35), χ2=5.913, P=0.015 0], but there was no significant difference among different genotypes in the metformin group. Compared to GG geno-type, AA genotype showed a trend of decrease in infection rate[38%(3/8) vs 72%(5/7), χ2=1.727, P=0.188 8]. Conclusion:Metformin has a favorable safety profile and may reduce the frequency of flares in SLE patients with low-grade lupus disease activity. The metformin therapeutic efficacy in SLE is relevant to the SLC47A1 gene polymorphism. Patients of the AA genotype may benefit most from metformin than those of the GG and GA genotypes.