[Leukocyte acid phosphatase activity in myocardial infarct]

Leucocytic acid phosphatase (AP) activity was measured cytochemically in 21 myocardial-infarction patients aged 37 to 57. Neutrophil leucocytosis was found to result from an increase in the quantity of cells with high activity of the enzyme. Neutrophil AP activity was elevated during the first days of the infarction and dropped to the baseline level on day 14. Between days 7 and 14, the numbers of lymphocytes with cytoplasmatic AP localization were reduced, suggesting lysosome stabilization at this stage of myocardial infarction.