Cell-mediated cytotoxicity to cardiac cells of lymphocytes from patients with primary myocardial disease.

The etiology of primary myocardial disease is unknown. With the advent of immunologic technics, an immune process related to primary myocardial disease has been sought, but none has been elucidated as diagnostic or causative. The authors attempted to study the possibility of a cell-mediated component in the etiology of primary myocardial disease. Cell-mediated immunologic injury of cultured, human myocardial cells was studied in cells from patients with primary myocardial disease and controls by means of a 51chromium-release method. Significant lymphocytic cytotoxicity against myocardial cells was detected in cells from 23 (30%) of 73 patients with primary myocardial disease, compared with two (4%) of 49 normal, healthy control subjects. Significant cytotoxicity was also observed in cells from 36 (24%) of 148 patients who had other cardiac diseases, mainly rheumatic and atherosclerotic diseases. No group showed cytotoxicity against a long-term culture of Chang hepatic cells. No clinical correlation between the severity of the disease and increased cytotoxicity could be found. It is concluded that lymphocytic reactivity against myocardial cells probably results from myocardial damage due to a variety of causes, and that it is not specific for primary myocardial disease.