The associations of HLA-DRB1 gene polymorphisms with late-onset myasthenia gravis: a meta-analysis

Background Late-onset myasthenia gravis (LOMG) is one of the major subgroups of the MG. Intensive evidence suggested that polymorphisms in HLA-DRB1 gene were associated with LOMG risk, but the results remained inconsistent. Therefore, a meta-analysis is conducted to make a more precise evaluation between HLA-DRB1 alleles and LOMG. Methods The PubMed, EMBASE, Cochrane library, Chinese National Knowledge Infrastructure (CNKI), and Wan Fang and Technology of Chongqing (VIP) Database were searched for eligible studies. The pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were applied to assess the association between HLA-DRB1 alleles and LOMG. Results A total of 11 studies involving 5513 people were included in our meta-analysis. The results showed that DRB1 07 and 0403 alleles were risk factors for LOMG (1.83 [1.12, 2.98], P = 0.02; 7.05 [2.62, 18.92], P = 0.0001, respectively), while DRB1 0301 and 1301 alleles were identified as protective factors for LOMG (0.44 [0.31, 0.62], P < 0.00001; 0.38 [0.23, 0.62], P = 0.0001, respectively). As for the HLA-DRB1 04 and 14 alleles, our subgroup analysis showed that there were significant associations between these alleles and LOMG in Caucasians (2.21 [1.14, 4.27], P = 0.02; 2.82 [1.29, 6.14], P = 0.009, respectively). Conclusions These results confirmed the association of DRB1 alleles (0301, 04, 0403, 07, 1301, and 14) and LOMG, which might provide potential promising biomarkers for prediction of LOMG risk.