WHO International Standards for the diagnosis and treatment of bleeding and thrombotic disorders

Global harmonisation in the diagnosis and treatment of bleeding disorders relies on the availability of WHO International Standards (IS) which define the International Unit (IU) for coagulation factors and related therapeutics. NIBSC has a long history in this area beginning in the 1970s with the establishment of the WHO 1st IS for Factor VIII Concentrate which was developed to quantify and harmonise the potency of concentrated preparations of coagulation factor VIII. Since then over 40 different WHO IS have been established to support diagnostics and therapeutics in all areas of haemostasis.

Enquiries on WHO International Standards: enquiries@nibsc.org Standards catalogue: https://www.nibsc.org/products/brm_product_catalogue.aspx

Newly Established Standards in 2017-19

• Activated Factor X (FXa), human purified – WHO Reference Reagent (15/102) >
• Factor XII (activity and antigen) in plasma (15/180) - WHO 1st International Standard
• Activated Factor IX (FIXa), human, purified (14/316) – WHO 2nd International Standard
• Factor V (activity and antigen) in plasma (16/374) – WHO 2nd International Standard
• von Willebrand factor:GPIb binding (GPIbR and GPIbM methods) (07/316) – WHO 1st International Reference Reagent (plasma)
• Streptokinase (16/358) – WHO 4th International Standard
• Factor XIII B subunit (total), plasma (02/206) – WHO 1st International Standard

Established WHO International Standards

WHO International Standards and Reference Reagents - therapeutics and purified coagulation factors

WHO International Standards and Reference Reagents - diagnostic

IS – International Standard; IRP – International Reference Panel; RR – Reference Reagent

British Standards and NIBSC Reference Materials