THE HEMOLYTIC-ACTIVITY OF HOMOCYSTEINE IS INCREASED BY THE ACTIVATED POLYMORPHONUCLEAR LEUKOCYTES

Homocysteine is an accepted risk factor when its plasma level exceeds the physiological upper limit of 12 mu mol/L. We found in vitro that h omocysteine is able to lyse the erythrocytes (RBCs) at higher concentr ations than 15 mu mol/L only when activated polymorphonuclear leukocyt es (PMNL) are present. The hemolytic effect of homocysteine was higher in RBCs obtained from cardiac catheterized patients with 100% stenosi s of the coronary arteries. Homocysteine was also able to increase the activation in vitro of PMNLs triggered by opsonized zymosan. The hemo lytic action of homocysteine was found to be dependent on the ratio of PMNLs to RBCs. This relationship may help to explain the great indivi dual variations in the hemolytic activity noticed in blood obtained fr om cardiac catheterized patients, and also may explain the mild anemia in some patients suffering from cardiovascular disease. (C) 1996 Acad emic Press. Inc.