Is apoptosis a diagnostic marker of acute myocardial infarction? An autopsy study comparing histologic, immunohistochemical, TUNEL, and DNA electrophoresis evidence

Objective.-To investigate and quantify the presence of apoptosis in early m yocardial ischemia in humans. Methods.-Histologic sections from the left and right ventricles of 16 heart s with impending myocardial infarction were stained with terminal deoxynucl eotidyl transferase-mediated deoxyuridine 5-triphosphate nick end labeling (TUNEL) method and with antibodies to p53, bcl-2, cpp32, FAS, FAS-L, and ba r. DNA electrophoretic analysis was also performed. Results.-According to the inclusion criteria, all 16 cases showed morpholog ic changes consistent with ischemia and/or reperfusion. TUNEL results were positive in 14 of the 16 ischemic areas. Unexpectedly, they were also posit ive in "remote from ischemia" myocardium of both the left and right ventric les. DNA electrophoretic analysis confirmed the results of TUNEL. Immunohis tochemistry was uniformly negative, probably because of autolysis phenomena . Conclusions.-We showed that apoptosis precedes necrosis in humans, but the detection of apoptosis cannot be used as a diagnostic tool, since it can al so be triggered by nonischemic events.