Thromb Haemost 2016; 115(03): 543-550
DOI: 10.1160/th15-03-0212
Coagulation and Fibrinolysis
Schattauer GmbH

The incidence and treatment of bleeding episodes in non-severe haemophilia A patients with inhibitors

Alice S. van Velzen
1   Department of Pediatric Hematology, Emma Children’s Hospital, the Academic Medical Center, Amsterdam, the Netherlands
,
Corien L. Eckhardt
1   Department of Pediatric Hematology, Emma Children’s Hospital, the Academic Medical Center, Amsterdam, the Netherlands
2   Department of Vascular medicine, Academic Medical Center, Amsterdam, the Netherlands
,
Nina Streefkerk
1   Department of Pediatric Hematology, Emma Children’s Hospital, the Academic Medical Center, Amsterdam, the Netherlands
,
Marjolein Peters
1   Department of Pediatric Hematology, Emma Children’s Hospital, the Academic Medical Center, Amsterdam, the Netherlands
,
Daniel P. Hart
3   Royal London Hospital, Bart’s and The London School of Medicine and Dentistry, London, UK
,
Karly Hamulyak
4   Maastricht University Medical Center, Maastricht, the Netherlands
,
Robert Klamroth
5   Vivantes Klinikum im Friedrichshain, Berlin, Germany
,
Karina Meijer
6   University Medical Center Groningen, Groningen, the Netherlands
,
Marten Nijziel
7   Maxima Medical Center, Eindhoven/Veldhoven, the Netherlands
,
Piercarla Schinco
8   San Giovanni Battista “Molinette” Hospital, Turin, Italy
,
Thynn T. Yee
9   Royal Free Hospital, London, the UK
,
Johanna G. van der Bom
10   Center for Clinical Transfusion Research, Sanquin Research and Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands
,
Karin Fijnvandraat
1   Department of Pediatric Hematology, Emma Children’s Hospital, the Academic Medical Center, Amsterdam, the Netherlands
,
for the INSIGHT study group› Author Affiliations
Further Information

Publication History

Received: 09 March 2015

Accepted after major revision: 13 October 2015

Publication Date:
20 March 2018 (online)

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Summary

The development of an inhibitory antibody in non-severe haemophilia A patients may aggravate the bleeding phenotype considerably. Effective treatment of bleeding episodes may be challenging, with ensuing severe complications. At present, evidence is scarce for optimal treatment of bleeding episodes in this patient group. The aim of this study was to describe the incidence and the treatment of bleeding episodes in inhibitor patients in a population-based unselected cohort of non-severe haemophilia A patients with clinically relevant inhibitors. Data were available for 100 of the 107 non-severe haemophilia A patients (factor VIII (FVIII) baseline, 2–40 lU/dl) from 29 centres in Europe and one centre in Australia who had developed a clinically relevant inhibitor between 1980 and 2011. The majority (89 %) of the patients were treated during the inhibitor period for bleeding episodes or a surgical intervention: 66 % needed treatment for bleeding episodes, at a median annual bleeding rate (ABR) of 1.1 (interquartile range (IQR) 0.1–2.5) and a median total of 2 (IQR 1–6) bleeding episodes. Compared to the median ABR before inhibitor development of 0.095 bleeds per year (IQR 0.02–0.42), the increase in ABR is more than a 10-fold. More than 90 % of the bleeding episodes were treated with only one type of product, most frequently (51 %) FVIII concentrates. This study provides the incidence of bleeding episodes and treatment choices in non-severe haemophilia A patients with inhibitors. The 10-fold increase to a median ABR of 1.1 episodes per year emphasizes the impact of inhibitor development for non-severe haemophilia A patients.

* A complete list of the members of the INSIGHT study group appears in the Appendix.