Morphologic findings in human cardiac allografts.

Morphologic findings in human cardiac allografts from 13 patients are presented. In the acutely rejected cardiac allograft there was a cellular infiltrate consisting of large lymphocytes and varying numbers of polymorphonuclear leukocytes, eosinophils, and histiocytes in the myocardium and arterial intima. The coronary arteries frequently exhibited degeneration, acidophilia, and vacuolation of the tunica media. In the cases with chronic cardiac allograft rejection there was obliterative fibrous thickening of the arterial intiina with medial necrosis. Focal areas of myocardial necrosis and fibrosis were present along with a myocardial infiltrate of mononuclear cells. In most patients who died of causes other than rejection, there was evidence of an immunologic response. Rejection has not been regarded as an "all or none" phenomenon. There was indication in this series that survival was related to histocompatibility.