Hemostatic variables in nephrotic patients

The paper reviews data in the literature as well as the authors' own investigations, performed during the last seven years, concerning the hemostatic balance in nephrotic patients. The obviously increased plasma levels of fibrinogen, fibronectin, fibrin-stabilizing factor XIII, clotting factors V and VIII, von Willebrand factor as well as the enhanced platelet aggregability of such patients, associated with a decreased plasma antithrombin III, are compatible with a thrombotic tendency. On the other hand the increased plasma protein C may provide a compensative antithrombotic mechanism. A rather complex behaviour of the fibrinolytic system was noted in the nephrotic syndrome. Actually the enhanced release of tissue plasminogen activator (t-PA) from the endothelia of nephrotic patients is accompanied by an accelerated lysis of dilute blood clots, although the inhibitors of fibrinolysis such as alpha 2-macroglobulin and alpha 2-antiplasmin are increased. Failure or exhaustion of the compensative antithrombotic mechanisms would accentuate the hemostatic imbalance and favour the occurrence of thrombotic events. It is considered that increased urinary loss of antithrombin III and the enhanced hepatic synthesis of clotting factors would represent the main mechanisms involved in the production of this precarious hemostatic balance of nephrotic patients.