Immunoglobulin binding in cardiomyopathic hearts.

Bound gamma globulin was demonstrated by the direct immunofluorescent technique in heart tissue from three patients with severe congestive cardiomyopathy. In two of these patients complement (,81C) was also bound to the heart muscle. Heart tissue from one of six patients who died of myocardial infarction showed a trace of bound gamma globulin, but no bound complement. During life, the heart in advanced cardiomyopathy may preferentially fix heart-reactive immunoglobulins to specific sarcolemmal and subsarcolemmal antigens, and antiheart antibody may not be detectable in the serum.