The possible value of synthetic peptides in the diagnosis and therapy of myocarditis and dilated cardiomyopathy.

The adenine nucleotide translocator (ANT) and myosin have been shown to be major autoantigens in myocarditis and dilated cardiomyopathy. We studied the use of synthetic peptides, with sequences derived from ANT and myosin, as antigens in screening tests for autoantibodies in myocarditis (MC) and dilated cardiomyopathy (DCM) and as absorbents for specific elimination of autoantibodies from the sera of patients. Using computer prediction of the secondary structure of the ANT and myosin we identified two sequences of the ANT and three sequences of myosin as possible main antigenic determinants. Using overlapping synthetic peptides and antibodies against them, the antigenicity of the selected determinants was shown. Of 72 sera from patients with MC or DCM 45 (62.5%) bound to the peptides derived from ANT, 32 (44.4%) reacted with the sequences from myosin, in contrast to healthy controls. Using the peptides from the ANT or myosin immobilized on thiopropyl-sepharose, more than 95% of the autoantibodies could be removed specifically from the positive sera. The results demonstrate the usefulness of synthetic peptides as antigens in antibody screening tests in MC and DCM and offers a new approach to the therapy of inflammatory heart disease by specific elimination of autoantibodies.