Effect of rFVIIa on clot formation and clot lysis time in plasma from patients with severe hemophilia A.
(A) Increase in clot lysis time on addition of increasing concentrations of rFVIIa (closed symbols). The increase in clot lysis time on addition of 500 U/mL rFVIIa could be completely abolished by addition of CPI (open symbol). (B) Mean clot lysis times of 17 patients with severe hemophilia A on addition of increasing concentrations of rFVIIa. At concentrations of rFVIIa of 31.3 U/mL and higher, the increase in clot lysis time was statistically significant. Error bars indicate SEM. *P < .01 versus clot lysis time in the absence of rFVIIa. (C) The data from panel A were fitted by an exponential function. From this curve the concentration of rFVIIa required for half maximal prolongation of clot lysis time (Clys½-VIIa) was calculated. (D) The decrease in clotting time on addition of rFVIIa. These data were fitted by an exponential function and from this curve the concentration of rFVIIa required for half maximal reduction of clotting time (Cclot½-VIIa) was calculated.
