EFFECT OF LEUKOCYTE PRODUCTS ON PLATELET THROMBUS FORMATION, COAGULATION AND SPONTANEOUS THROMBOLYSIS, AS MEASURED FROM NATIVE HUMAN BLOOD,IN-VITRO

Contribution of leucocytes to formation and lysis of arterial (platele t) thrombi was investigated. Secretory products of polymorphonuclear l eucocytes (PMNs) during phagocytosis and cell lysates were prepared fr om eight volunteers. Platelet-rich thrombi were formed in flowing nati ve human blood either by shear-stress or by collagen fibre, by haemost atometry. Tested in eight volunteers, PMN products significantly enhan ced both thrombotic reactions and induced lysis of these thrombi. A sp ecific inhibitor of leucocyte proteases (eglin c) inhibited platelet r eaction to shear-stress and collagen and spontaneous thrombolysis. Our findings provide further evidence for the prothrombotic and potent th rombolytic effect of leucocytes associated with an arterial thrombus.