Abstract
Objectives: Previous published data indicated that interleukin-21 (IL-21) gene polymorphisms were shown to associate with multiple autoimmune diseases (ADs), but the results remain inconclusive. The aim of this study was to perform a meta-analysis to assess the overall association between IL-21 gene polymorphisms (rs907715, rs2221903) and multiple ADs. Methods: All eligible case–control studies were searched in the PubMed and Embase database. A meta-analysis was conducted on the association between the IL-21 gene variants and ADs using: (1) allelic contrast, (2) homozygote contrast, (3) the recessive model, and (4) the dominant model. Results: A total of 12 relevant studies including 10 535 cases and 19 356 controls were enrolled in this meta-analysis. A significant association between IL-21 rs907715 gene polymorphism and AD was found under the allelic (OR: 1.102, 95% CI: 1.057–1.149, p = 0.000), homozygous (OR: 1.220, 95% CI: 1.089–1.368, p = 0.001), dominant (OR: 1.160, 95% CI: 1.027–1.309, p = 0.017), and recessive genetic model (OR: 1.119, 95% CI: 1.055–1.187, p = 0.000) among Caucasian populations. However, there was no significant association between IL-21 rs2221903 polymorphism and AD in different genetic models. Conclusions: Data from the present study suggest that the IL-21 rs907715 polymorphism might be associated with multiple ADs susceptibility in Caucasians. Especially, the allele G of intronic rs907715 in IL-21 confers increased risk of ADs.
Declaration of interest
This work was partly supported by grants from the National Natural Science Foundation of China (30830089). The authors declare no conflict of interests.