Five case-control studies were included in the present meta-analysis to assess the association between HLA-DRB1*1401, HLA-DRB1*0901, HLA-DRB1*0301, and idiopathic dilated cardiomyopathy.
Two haplotypes were associated with increased risk of primary DCM: DRB1*0401/DQB1*0302 (OR = 4.53, P = 0.002) and DRB1*0401/DQB1*0401 (OR = 9.42, P = 0.004).
The frequency of the DRB1*04 allele was low in probands with the disease (3/20, 15%); heterozygozity for DRB1*03/DRB1*04, known to increase susceptibility to IDDM1, was identified in 2 of 20 DCM probands (10%).
A two-locus analysis suggested that these two genetic markers (SOD2-VV genotype and DRB1*1401) may play a synergistic role in controlling the susceptibility to nonfamilial IDC.
The frequencies of DRB1*1401 (15.4% v 4.5%, RR = 3.90, P < 0.0005, Pc < 0.03), DQB1*0503 (14.1% v 5.4%, RR = 2.93, P < 0.007) and DRB1*1401-DQB1*0503 haplotype (11.5% v 1.5%, RR = 8.24, P < 0.00001, Pc < 0.01) were increased in the DCM patients.