Alcoholic cardiomyopathy versus chronic myocarditis--immunohistological investigations with LCA, CD3, CD68 and tenascin

Dilated cardiomyopathy (DCM) is a disorder of unknown aetiology characterized by the left ventricular cavity enlargement and wall thinning associated with reduced left ventricular wall motion. DCM in chronic alcoholics is supposed to be caused by alcohol induced myocardial damage (alcoholic cardiomyopathy). Nevertheless, cardiotropic viruses, such as enteroviruses have long been suspected as causative agents for at least some forms of DCM. In the present study, 13 cases of DCM in chronic alcoholics were investigated with qualification and quantification of infiltrating leucocytes using immunohistological antibodies against leucocyte common antigen (LCA), T-lymphocytes (CD3) and macrophages (CD68). In addition, the expression of tenascin, playing a role in the initiation of fibrotic changes, was examined. All antigens were known to be possibly enhanced in cases of chronic myocarditis. Using these immunohistological techniques, 2 out of 13 cases had evidence for chronic inflammatory myocardial alterations in the sense of lymphocytic infiltrates (>2.0 CD3 T-lymphocytes/visual field at 400 x (HPF); >7 CD3 T-lymphocytes per mm(2)). These cases were diagnosed as having inflammatory cardiomyopathy. The other cases without myocardial inflammation were diagnosed as idiopathic/alcoholic DCM.