Role of factor VIII on activated protein C resistance ratio in inflammatory diseases.

ABSTRACT

Activated protein C resistance ratio (APC-Rr), factor VIIIC (FVIIIC) and plasma fibrinogen levels were studied in patients with inflammatory disease. The patient mean APC-Rr was significantly lower than in the control group. This decreased ratio in inflammatory diseases appeared to be connected with increased FVIIIC. Moreover, supplementation of plasmas with purified factor VIII decreased the APC-Rr in plasma from both groups, and suppressed the difference between groups. These data suggest that factor VIIIa and factor Va compete for protein C-catalysed cleavage. Ratios were identical in both groups when FVIIIC level was lowered by dilution in factor V deficient plasma.