Physiology and morphology of blood coagulation in polycythemia vera

¹ Division of Cardiovascular Disease, Department of Laboratories and Department of Medicine, Henry Ford Hospital, Detroit, Michigan

The observation that red cells fall out of the clotted blood in polycythemia vera has been documented previously. This phenomenon appears in all patients with initial thrombocytosis but continues to occur even when the red cell mass and platelet numbers come under control. The only known coagulation defect is a pronounced reduction of platelet factor 3 in the platelets. In this investigation, platelet-plasma clots from normal individuals and polycythemia vera patients were sectioned and stained at various intervals during coagulation and clot retraction. Great disorganization of the platelet-fibrin network was observed in the polycythemia vera clots when compared with the normal clots, and it was apparent that the red cells could easily slip through the openings in the network.