Abstract Number: PB0783
Meeting: ISTH 2020 Congress
Background: Acquired hemophilia A (AHA) is a rare bleeding disorder marked by the development of autoantibodies to factor (F) VIII. Elevation of factor VIII activity (FVIII:C >150 IU/dl) has been reported in AHA patients who achieved remission during immunosuppression therapy.
Aims: We evaluated the comprehensive coagulation function in AHA patients with elevation of FVIII:C.
Methods: We performed clot wave form analysis (CWA), triggered by tissue factor and ellagic acid, and thrombin generation assay (TGA) by tissue factor and ellagic acid in eight AHA patients. We measured protein S and protein C activities as anticoagulant factors measured by activated partial thromboplastin time (APTT) based assay.
Results: Medians (range) of FVIII:C and von Willebrand factor antigen were 219 (151-344) IU/dl, and 370 (210-433) IU/dl, respectively. CWA parameter, adjusted maximum coagulation velocity (ad|min1|), was used. Two patients (ad|min1|; 6.0, and 6.4) showed below control range (ad|min1|; 7.7±0.5). Five patients (ad|min1|; 7.2-8.2) were within control range. Only one patient (ad|min1|; 9.0) showed the higher value than that of control range. Peak thrombin was used for TGA parameter. Five patients (peak thrombin; 236-391 nM) showed the lower than that of control range (463±21 nM). One patient (peak thrombin; 449 nM) was within control range. Only two patients (peak thrombin; 554, and 577 nM) showed the higher peak thrombin than that of control range. On the other hand, protein S activities in all AHA patients were normal [median (range); 107 (57-118) IU/dl]. Interestingly, protein C activities in six of eight AHA patients were high [median (range); 177 (165-206) IU/dl]. Two AHA patients showed normal protein C activities (112 and 144 IU/dl).
Conclusions: Majority of AHA patients with marked elevation of FVIII:C did not show high coagulation function according to the comprehensive coagulation function assays.
To cite this abstract in AMA style:Takeyama M, Nogami K, Shibasaki F, Sasai K, Shima M. Global Coagulation Analysis for Acquired Hemophilia A Patients with the Marked Elevation of Factor VIII Activity during Remission Phase [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/global-coagulation-analysis-for-acquired-hemophilia-a-patients-with-the-marked-elevation-of-factor-viii-activity-during-remission-phase/. Accessed December 3, 2021.
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