HLA-DR4 antigen and idiopathic dilated cardiomyopathy susceptibility: a meta-analysis involving 11,761 subjects.

Idiopathic dilated cardiomyopathy (IDC) has been hypothesized as a multifactorial disorder initiated by an environment trigger in individuals with predisposing human leukocyte antigen (HLA) alleles. Published data on the association between HLA-DR4 antigen and IDC risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Studies in English-language articles were identified by a search of PubMed and Embase database (inception to June 2010). A total of 19 case-control studies including 1378 cases and 10,383 controls provided data on the association between HLA-DR4 antigen and genetic susceptibility to IDC. Overall, statistically elevated frequency of HLA-DR4 allele [OR (odds ratio), 1.58; 95% CI (confidence interval), 1.21-2.07; P = 0.0009] was found in patients with IDC compared with controls. When stratified by myocardial biopsy or non-biopsy cases, statistically increased risks were found for IDC in both subgroups. In the subgroup analysis by ethnicity, significantly increased risk was found among Europeans from 12 case-control studies (OR, 1.54; 95% CI, 1.11-2.12; P = 0.009). In conclusion, our results suggest that HLA-DR4 antigen is a low-penetrant risk factor for developing IDC in Europeans.