Yaoi H, Shida Y, Ogiwara K, Kitazawa T, Shima M, Nogami K. Emicizumab enhances thrombus formation in vitro under high shear flow conditions in whole blood from patients with type 1 and type 3 von Willebrand disease.
Haemophilia 2022;
28:694-701. [PMID:
35478475 DOI:
10.1111/hae.14581]
[Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 03/30/2022] [Accepted: 04/19/2022] [Indexed: 12/18/2022]
Abstract
INTRODUCTION
Type 1 and type 3 von Willebrand disease (VWD) are caused by partial and complete, quantitative deficiency of von Willebrand factor (VWF), respectively, and factor (F)VIII/VWF complex concentrates are used for haemostatic treatment. Emicizumab, mimics activated FVIII, reduces bleeding in haemophilia A patients. The effects of emicizumab on haemostasis in both types of VWD remain to be fully established, however.
AIM
To examine the effects of emicizumab on thrombogenesis in type 1 and type 3 VWD.
PATIENTS/METHODS
Perfusion chamber experiments under high shear conditions (2500 s-1 ) combined with immunostaining were performed using whole blood samples from patients with type 1 (VWF:Ag 25 U/dl) and type 3 VWD (<1.0 U/dl).
RESULTS
The addition of FVIII (1 U/ml) to type 1 blood did not affect thrombus formation, whilst supplementation with VWF (1.6 U/ml) or FVIII/VWF (1 U/ml/1.6 U/ml) enhanced thrombogenesis to a similar extent. FVIII/VWF promoted thrombus formation significantly more than VWF alone, however, in type 3 blood. Emicizumab (100 μg/ml) augmented thrombus formation in type 3 blood compared to FVIII, and this potency seemed to be somewhat greater than that of VWF. Surface coverage of formed thrombus in type 3 VWD was less than that in type 1 VWD, but thrombus height was comparable in both. The addition of emicizumab to type 3 blood enhanced thrombin generation and fibrin formation compared to control IgG.
CONCLUSION
Emicizumab promoted mechanisms of thrombus formation in vitro in type 3 and type 1 VWD, suggesting the possibility of alternative therapeutic protocols in these patients.
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