Evaluation of an automated chromogenic assay for Factor VIII clotting activity measurement in patients affected by haemophilia A

Introduction The original one‐stage clotting assay is still the most widely used method to measure Factor VIII clotting activity (FVIII:C) in patients with haemophilia A (HA), although the use of chromogenic assays is increasing significantly. Aim Evaluation of the analytical performance and diagnostic accuracy of BIOPHEN™ FVIII:C (HYPHEN BioMed, Neuville‐sur‐Oise, France) assay on Sysmex CS‐2400 (Sysmex, Kobe, Japan) analyser. Methods Sixty patients with haemophilia A (HA; any severity) and 120 healthy Italian subjects were included. All the assays were performed on citrate platelet‐poor plasmas stored at −80°C. Chromogenic BIOPHEN™ FVIII:C was compared with the one‐stage assay using Actin FS and Factor VIII deficient plasma (Siemens Healthcare Diagnostics, Marburg, Germany) on Sysmex CS‐2400 and with another chromogenic automated assay (COAMATIC™ Factor VIII, CHROMOGENIX on ACL TOP analyzer; Instrumentation Laboratory, Milan, Italy). Results Intra‐assay and inter‐assay coefficient of variation were