Association between vitamin D receptor gene BsmI, FokI, ApaI and TaqI polymorphisms and the risk of systemic lupus erythematosus: a meta-analysis

Association studies of vitamin D receptor (VDR) gene polymorphisms and the risk of systemic lupus erythematosus (SLE) have yielded conflicting results in different backgrounds. We aimed to evaluate the association between VDR gene polymorphisms and SLE risk. A predefined electronic databases search was performed to identify eligible studies that were related to the association of VDR gene BsmI, FokI, ApaI or TaqI polymorphism with SLE risk. Either a fixed-effects model, or in the presence of heterogeneity, a random-effects model was used to calculate the pooled odds ratios (ORs) and its corresponding 95 % confidence interval (CI). A total of 11 studies with 1,621 cases and 1,883 controls were included in this meta-analysis. BsmI B allele was associated with the onset of SLE for overall populations (OR 1.726, 95 % CI 1.214–2.455) and Asians (OR 1.952, 95 % CI 1.135–3.355). FokI FF genotype was correlated with the susceptibility of SLE for Asians (OR 1.469, 95 % CI 1.005–2.148). FokI T/C and TaqI polymorphisms were not associated with SLE risk for Caucasians. There was no significant association between ApaI polymorphism and SLE risk for overall populations, Asians and Caucasians. No evidence of publication bias was observed. In conclusion, BsmI B allele may be a risk factor for SLE onset among overall populations and Asians, and FokI FF genotype is a risk factor for SLE susceptibility in Asians. However, more studies should be performed in the future.