RESUMEN
This retrospective cohort study investigated the association between factor 8 (F8) genotype severity and factor VIII (FVIII) levels during pregnancy for 52 women (64 pregnancies) who were heterozygous carriers of mild, moderate or severe haemophilia A. There were no significant differences in FVIII levels for carriers of mild, moderate or severe haemophilia A at baseline [mean (SD) level: mild, 0·78 (0·22); moderate, 0·83 (0·33); severe, 0·70 (0·25) iu/ml; P = 0·81] or in the third trimester [mean (SD) level: mild, 1·42 (0·28); moderate, 1·47 (0·41); severe, 1·37 (0·49) iu/ml; P = 0·80). Post-partum haemorrhage rates were higher for carriers of severe haemophilia A (13/24; 54·2%) compared to carriers of mild haemophilia A (four of 14; 28·6%).
Asunto(s)
Factor VIII/genética , Hemofilia A/genética , Hemorragia Posparto/genética , Tercer Trimestre del Embarazo/sangre , Adolescente , Adulto , Factor VIII/análisis , Femenino , Genotipo , Hemofilia A/complicaciones , Hemofilia A/diagnóstico , Heterocigoto , Humanos , Incidencia , Mutación , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo de Nucleótido Simple , Hemorragia Posparto/epidemiología , Hemorragia Posparto/etiología , Embarazo , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
INTRODUCTION: Extended half-life factor IX concentrates (EHL-FIX) can be administered weekly to prevent bleeding for persons with severe haemophilia B. We report the experience of a large UK haemophilia comprehensive care centre using low dose EHL-FIX for persons with severe haemophilia B. AIM: The low doses used in real world are approximately half of the doses used in clinical trials. We aim to assess the efficacy and safety of low dose EHL-FIX. METHODS: Data from a cohort of 13 patients who were switched from standard half-life factor IX (SHL-FIX) to Alprolix® (mean dose 31.5 IU/kg) and seven patients who switched from standard half-life factor IX to Idelvion® (mean dose 20.2 IU/kg) were included. RESULTS: The median annualized bleeding rate was similar for SHL-FIX (median 3, interquartile range [IQR] 1-5) and EHL-FIX (median 3, IQR 1-5.25). Quality of life scores, measured using the European Quality of Life 5 Dimensions assessment were similar for SHL-FIX (median 0.76, IQR: 0.63-0.84) and EHL-FIX (median 0.79, IQR: 0.58-0.88). CONCLUSION: This study shows that EHL-FIX given at low doses can be effective for prevention of bleeding for persons with severe haemophilia B.