Fibrinogen interaction with activated polymorphonuclear leukocytes studied by chemiluminescence

Fibrinogen (FB) is an acute phase protein. It is recognized as an independent risk factor in the plasma of patients with coronary heart disease (CHD). The plasma FB level is also significantly increased in inflammation and neoplasms. We performed an in vitro study showing that the chemiluminescence (CL) emission produced by zymosan-activated polymorphonuclear leukocytes (PMNL) was directly related to the concentration of FB, fibrinopeptide A or FB-degradation products (FDP). Fibrin inhibited CL emission. Our results emphasized the role of FB as an independent risk factor in CHD but related to the level of activated polymorphonuclear leukocytes in the plasma. Activated PMNL may contribute to an elevated plasma level of FDP as a consequence of enhanced enzyme-dependent degradation of FB. Our results indicate that the role of FB as independent risk factor in CHD depends on the level of activated polymorphonuclear leukocytes in the plasma.