Association of Human Leukocyte Antigen Class II with Susceptibility to Primary Biliary Cirrhosis: A Systematic Review and Meta-Analysis

Purpose: Several previous studies suggested that HLA-Class II may be associated with susceptibility to primary biliary cirrhosis (PBC), but data from individual studies remain controversial. Therefore, a systematic review and meta-analysis is needed to comprehensively evaluate the association between HLA-Class II and PBC risk. Methods: All published reports of an association between HLA class II and PBC risk were searched in PubMed, EMBASE (updated to 22 May 2012). ORs with 95% confidence intervals (CIs) were extracted from each included study and the meta-analysis was performed using the fixed-or random-effects model. Results: A total of 3,732 PBC patients and 11,031 controls from 34 studies were included in the meta-analysis. An assessment of study quality revealed that the majority of studies included (18 studies) were of high quality. The serological group DR8 was found to be a risk factor for PBC (OR = 2.82, 95% CI: 1.84-4.30). At the allelic level, HLA-DR*08 and HLA-DR*0801 were identified as risk factors for PBC (OR = 2.30, 95% CI: 1.76-3.00; OR = 3.23, 95% CI: 2.22-4.70, respectively), whereas HLA-DR* 11 and HLA-DR* 13 were potent protective factors (OR = 0.31, 95% CI: 0.27-0.38; OR = 0.62, 95% CI: 0.48-0.81, respectively). HLA-DQB1 and HLA-DQB1*0402 conferred a predisposition to PBC development (OR = 3.47, 95% CI: 2.35-5.13), whereas HLA-DQB1*0604 was protective against PBC (OR = 0.3, 95% CI: 0.18-0.58). No HLA-DPB1 allele was observed to be associated with PBC susceptibility (P > 0.05). Conclusions: The present study revealed that HLA-Class II components are closely associated with the development of PBC.