Increased fibrin polymerization rate in patients with primary antiphospholipid syndrome and systemic lupus erythematosus.

The main event in blood coagulation is the thrombincatalyzed conversion of fibrinogen into fibrin. This singular transformation of a soluble protein into an insoluble polymeric network occurs with faultless precision. Abnormalities of fibrin polymerization can lead to hemorragic and thrombotic disorders. Increased fibrinogen plasma concentration (Fg) and fibrin polymerization rate (FPR) could be additional risk factors associated with atherothrombosis in antiphospholipid syndrome (APS) and in systemic lupus erythematosus (SLE). Our objective was to investigate Fg and FPR in consecutive patients with APS and SLE. Thirty-nine patients and 31 age- and gender-matched healthy controls were studied. Sixteen patients had primary APS, 13 patients had SLE, and 10 patients had SLE plus APS. The mean of the FPR was significantly increased (0.2799 +/- 0.091) in patients with APS plus SLE as compared with the control group (0.2052 +/- 0.055) (p < 0.05). Fg was higher in APS plus SLE (3.15 g/L +/- 0.43) and in primary APS (3.03 g/L +/- 0.29) than in controls (2.87 g/L +/- 0.49). Our results demonstrated an increased FPR in patients with APS plus SLE. This phenomenon could be an additional risk factor for thrombosis in these autoimmune diseases.