Immunopathologic study of the myocardium in dilated cardiomyopathy

: Myocardial tissues of patients with dilated cardiomyopathy were studied by immunofluorescence. While immunoglobulin A fixation was observed in myocardial capillary wall and cardiomyocyte sarcolemma in the majority of patients (11 of 12), immunoglobulin G and C3 complement component were a rare finding. In the vessel wall of heart allografts immunoglobulin A fixation occurred 3-6 days after transplantation. As a result of the intensive immunosuppressive therapy which was used after the operation immunoglobulin A disappeared from heart allografts within 4-5 weeks. Immunoglobulin A fixation in the heart of patients with dilated cardiomyopathy is attributed to the anti-tissue or antivirus antibodies and probably is involved in the development of this disease.