Factor IX inhibitors in haemophilia B: A report of National Haemophilia Registry in China

Abstract

Introduction:The development of inhibitors against factor FIX (FIX) is the most serious complication of FIX replacement therapy in haemophilia B (HB) patients. Currently, only few cohorts of HB inhibitor patients have been reported worldwide.Aim: This Chinese nationwide study of HB inhibitor patients explored their risk factors for FIX inhibitor development and experience on their management. Methods:We retrospectively analysed patient characteristics, F9 genotypes, treatment strategies and outcomes of HB inhibitor patients registered to the Chinese National Registry and Patient Organization Registry.Results: Forty-four unique HB inhibitor patients were identified in 4485 unique HB patients registered by year 2021 to the two Registries. Inhibitor diagnosis were usually delayed and the low prevalence (.98%) may suggest some inhibitor patients were not identified. Their median age at inhibitor diagnosis was 7.5 (IQR, 3.0-14.8) years. Most

The importance and evolution of bleeding disorder registries

“…Utilizing data collected by the national haemophilia registry system, we described the demographics, epidemiology, clinical profile and treatment of patients with haemophilia in China. [3][4][5][6][7][8][9] In 2007−2019, 17,779 patients with haemophilia A (HA) were uploaded to the national haemophilia registry system. For those patients with factor VIII level available (N = 13,116), 6,519 had severe HA (49.7%), 4,788 had moderate HA (36.5%), and 1,809 had mild HA (13.8%).…”

“…6 Among them, 44 developed FIX inhibitors. 7 In the national registry system, 61 females had confirmed haemophilia. Among 45 post-menarcheal females, 21 (46.7%) had a history of heavy menstrual bleeding, but only three received treatments.…”

“…Utilizing data collected by the national haemophilia registry system, we described the demographics, epidemiology, clinical profile and treatment of patients with haemophilia in China 3–9 . In 2007−2019, 17,779 patients with haemophilia A (HA) were uploaded to the national haemophilia registry system.…”

“…Of those patients with records of disease severity ( N = 3258), 744 were severe, 1,945 were moderate, and 569 were mild 6 . Among them, 44 developed FIX inhibitors 7 …”

Overview of Patients with Hemophilia in China: Demographics, Diseases, Treatment, and Health Status

“…9,[14][15][16][17] Nevertheless, the national studies mostly describe the progression of building networks, registry systems, and treatment centers in China. 4,8,18 Scant evidence on the general status of hemophilia patients in mainland China, and these two studies are only limited to adults or shed light on specific types of hemophilia patients rather than all the hemophilia patients. 19,20 There is an urgent need to describe the landscape of the whole hemophilia population in China, based on national representatives and a relatively big sample with patients' self-reported real-world data, to reflect and update the overall status of their demographics, diseases, treatment, and health status.…”