HLA-DQB1* polymorphism and associations with dilated cardiomyopathy, inflammatory dilated cardiomyopathy and myocarditis.

To date, only weak associations have been reported between idiopathic dilated cardiomyopathy (DCM) and certain HLA class II alleles. Associations between HLA class II alleles and specific causes of DCM, especially myocarditis, have as yet not been systematically investigated. Typing of HLA DQB1* allele was performed using a sequence-specific primer-polymerase chain reaction technique in 22 unrelated patients with idiopathic DCM, 19 patients with myocarditis and normal left ventricular function, and 16 patients with myocarditis and impaired left ventricular function (i.e. inflammatory DCM). Controls comprised 44 patients without (inflammatory) cardiac disease and a population control. A significant association was found for presence of HLA DQB1*0303 with myocarditis without cardiac dysfunction. Weaker associations were seen for presence of HLA DQB1*0301 and absence of HLA DQB1*06 with inflammatory DCM. Additionally, allelic combination DQB1*02-DQB1*03 may be able to distinguish idiopathic from inflammatory DCM, and HLA DQB1*02 myocarditis with cardiac dysfunction from myocarditis without, if results are confirmed by larger prospective studies.