Dendritic cells: a candidate cell in injury response to myocardial infarction and a possible diagnostic tool for sudden death

Dendritic cells and mast cells are involved in the organization of inflammatory cell infiltrates in general, and in vascular wall in particular. The behaviour of these cells in myocardial infarction is still to be studied in detail. Myocardial samples were taken at autopsy from the left ventricle of subjects respectively affected by (1) acute myocardial infarction, (2) previous myocardial infarction, (3) coronary artery disease and (4) traumatic death assumed as controls. Tissue sections were stained with haematoxylin and eosin and immunohistochemistry; organ sections were also stained with triphenyltetrazolium. Loss of acidophilia and disappearance of nuclei and intercalated disks were found in acute infarction. Massive infiltration of dendritic cells was found in acute and previous infarction, while mast cell numbers were similar to controls. Localized lack of reactivity with triphenyltetrazolium, indicating lack of viable tissue, was observed only when autopsy was conducted within 48 h from death. The results indicate that dendritic cells react early to myocardial injury; they may be regulators of the inflammatory and scarring response in this tissue; their increase may be a useful marker of acute myocardial infarction.