A collaborative study to establish the 1st International Standard for factor XIII plasma

Area of Science:

• Biochemistry
• Hematology
• Clinical Chemistry

Background:

• An international collaborative study was conducted by 23 laboratories to establish the first International Standard (IS) for factor XIII (FXIII) plasma.
• The study was organized under the FXIII Standardization Working Party (SWP).

Purpose of the Study:

• To calibrate the 1st International Standard (IS) for factor XIII (FXIII) plasma.
• To ensure accurate and consistent measurement of FXIII activity and antigen levels globally.

Main Methods:

• Potency estimates for the candidate FXIII plasma (preparation Y) were calculated relative to local normal plasma pools.
• Both FXIII activity and antigen levels were assessed.
• Accelerated degradation studies were performed to evaluate the stability of the proposed standard.

Main Results:

• Preparation Y exhibited good agreement between laboratories for FXIII activity (GCV 11.5%, mean 0.91 U mL(-1)) and antigen levels (GCV 16.3%, mean 0.93 U mL(-1)).
• Commercial methods showed negligible differences in potency (approx. 1%).
• The standard demonstrated excellent stability, with predicted annual loss of <0.06% at -20°C.

Conclusions:

• Preparation Y was deemed suitable and potent by study participants and relevant scientific committees.
• Preparation Y was approved by the World Health Organization as the 1st IS for FXIII plasma.
• The established standard has an activity potency of 0.91 IU/ampoule and an antigen potency of 0.93 IU/ampoule.