2015-10-24-世界卫生组织-WHO_BS_2015.2261_Collaborative_study_report_on_Blood_Coagulation_Factor_IX_70页_1mb

The collaborative study focused on blood coagulation factor IX, aiming to add a FIX antigen value to the 4th International Standard for Factors II, VII, IX, X, Plasma, value assign the 5th WHO International Standard for Factor IX Concentrate and the Ph Eur BRP, and investigate the use of the standard as a potency standard for recombinant Factor IX.

Key findings included:

• A FIX antigen value of 0.90 IU/ampoule was assigned to the 4th International Standard for Plasma.
• Sample B (14/148) was established as the 5th WHO International Standard with a functional activity value of 10.5 IU/ampoule.
• High inter-laboratory variability was observed for recombinant samples, leading to the recommendation not to establish a recombinant International Standard due to concerns about potential confusion and shift in potency labeling.

The study involved multiple laboratories and assays, with plasma-derived samples showing good agreement, while recombinant samples exhibited significant discrepancies. The recommendations were supported by participants, except for one participant who opposed the recombinant standard.