A new hemophilia carrier nomenclature to define hemophilia in women and girls: Communication from the SSC of the ISTH

• Type of Material: Article
• Authors: Karin PM van Galen, Utrecht University; Roseline d'Oiron, Hôpital Bicêtre and Inserm U 1176; Paula James, Queen’s University; Rezan Abdul-Kadir, University College London; Peter A Kouides, University of Rochester; Roshni Kulkarni, Michigan State University; Johnny N Mahlangu, University of Witwatersrand; Maha Othman, Queen’s University; Flora Peyvandi, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinic; Dawn Rotellini, National Hemophilia Foundation; Rochelle Winikoff, Sainte‐Justine Hospital; Robert F Sidonio, Emory University
• Language: English
• Date: 2021-08-01
• Publisher: WILEY
• Publication Version: Final Published Version
• Copyright Statement: © 2021 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals LLC on behalf of International Society on Thrombosis and Haemostasis
• License: Creative Commons Attribution-NonCommercial 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1111/jth.15397
• Title of Journal or Parent Work: JOURNAL OF THROMBOSIS AND HAEMOSTASIS
• Volume: 19
• Issue: 8
• Start Page: 1883
• End Page: 1887
• Keywords: BAT; bleeding; Peripheral Vascular Disease; women's health; Life Sciences & Biomedicine; hemophilia; RANGE; Hematology; Cardiovascular System & Cardiology; phenotype; Science & Technology; PHENOTYPE; FACTOR-VIII; A CARRIERS
• Research Categories: Health Sciences, Medicine and Surgery; Health Sciences, Oncology

Abstract

Hemophilia A and B predominantly attracts clinical attention in males due to X-linked inheritance, introducing a bias toward female carriers to be asymptomatic. This common misconception is contradicted by an increasing body of evidence with consistent reporting on an increased bleeding tendency in hemophilia carriers (HCs), including those with normal factor VIII/IX (FVIII/IX) levels. The term HC can hamper diagnosis, clinical care, and research. Therefore, a new nomenclature has been defined based on an open iterative process involving hemophilia experts, patients, and the International Society on Thrombosis and Haemostasis (ISTH) community. The resulting nomenclature accounts for personal bleeding history and baseline plasma FVIII/IX level. It distinguishes five clinically relevant HC categories: women/girls with mild, moderate, or severe hemophilia (FVIII/IX >0.05 and <0.40 IU/ml, 0.01–0.05 IU/ml, and <0.01 IU/ml, respectively), symptomatic and asymptomatic HC (FVIII/IX ≥0.40 IU/ml with and without a bleeding phenotype, respectively). This new nomenclature is aimed at improving diagnosis and management and applying uniform terminologies for clinical research.