ANTI-BETA-RECEPTOR ANTIBODIES IN FAMILIAL CARDIOMYOPATHY - CORRELATION WITH HLA-DR AND HLA-DQ GENE POLYMORPHISMS

The presence of beta-receptor autoantibodies and their relationship to restriction fragment length polymorphisms of the human leukocyte anti gen (HLA) class II genes were studied in 42 affected and unaffected me mbers of a family with a heritable disorder of the conduction system a nd cardiac muscle. Antibodies were detected in 34% of all members (59% of affected and 22% of unaffected; p < 0.01). Significant differences between affected and unaffected individuals and between anti-beta-rec eptor antibody positive and negative individuals were noted in the pre valence of polymorphisms obtained with Tag I for the HLA-DR beta and H LA-DQ alpha genes. In affected individuals, there was a strong positiv e correlation between these polymorphisms and the presence of anti-bet a-receptor antibodies. These results suggest that autoimmune mechanism s under the control of the class II genes play an important role in th e pathogenesis of familial cardiomyopathy.