Antiphospholipid antibodies (APA) are known to be associated with thrombembolic events and/or recurrent foetal loss. Their possible action to the blood coagulation system seems to be various and could lead to prothrombotic tendency. An important mechanism involved in this process has been referred – the influence on the protein C inhibiting pathway. The aim of our study was to determine abnormalities in protein C pathway by the test ProC®global in patients with antiphospholipid antibodies. 126 patients and 64 controls were evaluated. ProC®global values were significantly lower (p < 0.001) in patients than in healthy persons and in patients who undervent venous thromebolism (p < 0.001) when comparing them with persons without this complication. Using ROC analysis we could determine cut off patients with higer risk of the thrombosis. In women ProC®global value < 0.8 were asociated with the 1.8-fold thrombotic risk increasing, in men ProC®global value < 0.71 with 1.7-fold.

        Key words: antiphospholipid antibodies, ProC®global, thrombosis, risk prediction