HLA-DRW4 antigen linkage in patients with hypertrophic obstructive cardiomyopathy.

To determine the association of histocompatibility (HLA) genes in patients with hypertrophic cardiomyopathy, we determined HLA-A, HLA-B, HLA-C, and HLA-DR specificities in 33 Japanese patients (15 with the obstructive type off hypertrophic cardiomyopathy, and 18 with the nonobstructive type). HLA-DRW4 was found in 73% of patients with hypertrophic obstructive cardiomyopathy, as compared to 33% of 144 normal controls (p < 0.005). HLA-DRW4 occurred in 33% of those with hypertrophic nonobstructive cardiomyopathy, and there was no significant difference as compared with controls. Thus, hypertrophic obstructive cardiomyopathy is associated with genes in the HLA-DR region and immunogenetic factors linked to HLA appear to play a role in the pathogenesis. This work is the first attempt at demonstration of HLA-DR antigen in hypertrophic cardiomyopathy.