Thrombelastographic monitoring of recombinant factor VIIa in acquired haemophilia

Monitoring of the global haemostatic capacity is desired to optimize the treatment with bypassing agents in inhibitor patients. Thrombelastographic methods have been used in ex vivo studies and were suggested useful to evaluate the individual response to bypassing agents. This study aimed at assessing changes in thrombelastographic profiles and their association to clinical outcome in patients treated with recombinant factor VIIa (rFVIIa). Ten patients with acquired haemophilia were treated with rFVIIa for acute bleeding. Thrombelastography was performed after activation with a small amount of tissue factor in samples obtained before and after in vivo administration of rFVIIa. In patients studied before and after a first dose, correction of the thrombelastographic profile was observed but did not predict cessation of bleeding. During steady-state dosing, the median Alpha angle tended to be higher in patients with a good clinical treatment response as compared with patients with a partial or poor response. Similar trends were observed for clotting time and clot formation time. A good clinical treatment response was more frequent in patients with a fully corrected trough-level thrombelastographic profile as compared with patients with an abnormal profile. However, a poor treatment response was observed also in a surgical patient with a normal thrombelastographic profile during steady-state dosing. In conclusion, thrombelastographic monitoring was sensitive to haemostatic changes in response to treatment with rFVIIa. In the limited number of patients studied here, a better clotting profile during steady-state dosing was associated with a better clinical treatment response.