Summary
There is increased interest in the relationship between plasma fibrinogen levels and
the incidence of coronary artery disease. The National Institute for Biological Standards
and Control (UK) has completed a study to establish an International Standard for
plasma fibrinogen. This study was conducted using a recommended assay procedure to
measure the clottable material present in the proposed lyophilised Standard (coded
89/644). Twenty-two laboratories from nine countries took part in the study and analysis
of the data allowed the calibration of 89/644 at 2.4 mg/ml clottable protein. Agreement
with this figure was established in two laboratories using three or more different
assays for plasma fibrinogen. Degradation studies of the proposed plasma fibrinogen
Standard suggested that no loss of clottable protein was observed when the lyophilised
material was stored at 20° C for 1 year.
The Fibrinogen Sub-Committee of the ISTH (Amsterdam, The Netherlands, June 1991) supported
the establishment of 89/644 as an International Standard. This collaborative study
will be presented to the Expert Committee on Biological Standardisation of the World
Health Organisation at their 1992 session. In the meantime 89/644 will be distributed
as the proposed International Standard for plasma fibrinogen measurement containing
2.4 mg/ ml clottable protein.