Factor VIII half life and clinical phenotype of severe hemophilia A

Karin Van Dijk*, Johanna G. Van Der Bom, Peter J. Lenting, Philip G. De Groot, Eveline P. Mauser-Bunschoten, Goris Roosendaal, Diederick E. Grobbee, H. Marijke Van Den Berg

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Background and Objectives. Patients with severe hemophilia A have considerably different factor VIII half-lives. Whether this is associated with their clinical characteristics has not been reported. The aim of this study was to describe the association of factor VIII half-lives with treatment and clinical characteristics of patients with severe hemophilia A, who have been treated with individually tailored prophylaxis. Design and Methods. Patients were selected from a single-center cohort of 214 patients with severe hemophilia, born between 1944 and 1995. To improve efficiency we measured factor VIII half-life in 42 patients selected from the extremes of the distribution of phenotypes of severe hemophilia. We assessed information on life-long joint bleeds and clotting factor consumption. Orthopedic outcome was assessed by the Pettersson score. Results. Among these patients with severe hemophilia, factor VIII half-life ranged from 7.4-20.4 hours (median 11.8 hours). A one-hour increase in factor VIII half-life was associated with 96 (95% confidence interval (Cl) 2-190) IU less clotting factor use per kg per year. Age was an important determinant of factor VIII half-life, and explained a large part of the association between factor VIII half-life and clotting factor consumption. The median number of joint bleeds per year and arthropathy were similar for patients with different half-lives. Interpretations and Conclusions. Among patients with severe hemophilia, treated prophylactically with clotting factor, those with a shorter factor VIII half-life required slightly more clotting factor to prevent joint bleeds and subsequent arthropathy than similar patients with a longer factor VIII half-life.

Original languageEnglish
Pages (from-to)494-498
Number of pages5
JournalHaematologica
Volume90
Issue number4
Publication statusPublished - Apr 2005

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