Association of HLA-DPB1 polymorphisms with rheumatoid arthritis: A systemic review and meta-analysis

Background: The current reports on the association between HLA-DPB1 alleles and rheumatoid arthritis (RA) results were controversial. Thus, we conducted a meta-analysis to assess whether DPB1 alleles are associated with increased risk of rheumatoid arthritis. Methods: Systematic searches on PubMed, Embase, Elsevier, CNKI (China National Knowledge Infrastructure), Wanfang data and Cochrane Library prior to July 2017 were performed. The pooled odds ratios (ORs) and 95% confidence interval (95% CI) was used to assess the association between frequencies of DPB1 alleles and RA patients. Results: Eight studies with 592 cases and 935 controls were included in this meta-analysis. Overall, the pooled ORs showed that frequencies of DPB1*0401 and *0601 were higher in the RA group compared with controls (*0401: OR: 1.586, 95% CI: 1.296-1.941, P < 0.001; *0601: OR: 1.921, 95% CI: 1.142-3.229, P = 0.014). Whereas, the frequencies of DPB1*0101, *0402 and *0501 were lower in the RA control than the controls (*0101: OR: 0.691, 95% CI: 0.481-0.993, P = 0.046; *0402: OR: 0.707, 95% CI: 0.555-0.902, P = 0.005; *0501: OR: 0.502, 95% CI: 0.329-0.767, P = 0.001). No associations were observed for DPB1*0201, *0202, *0301 and *0901 (*0201: OR: 1.129, 95% CI: 0.882-1.446, P = 0.335; *0202: OR: 0.840, 95% CI: 0.940-1.441, P = 0.527; *0301: OR: 0.769, 95% CI: 0.577-1.026, P = 0.074; *0901: OR: 1.221, 95% CI: 0.541-2.755, P = 0.630). Conclusions: This meta-analysis demonstrates that high frequency expression of DPB1*0401 and *0601 are significantly associated with susceptibility to RA, it may be a risk factor for occurrence of RA. Low frequency expression of DPB1*0101, *0402 and *0501 may be negatively associated with RA, it may be a protective factor for occurrence of RA.