Are Results of Fibrinogen Measurements Transferable?

Abstract

Fibrinogen concentration is routinely measured by several methods and the results may influence diagnostic and treatment strategies. It is therefore necessary that results are compatible and transferable between laboratories. In the present study, it is shown that commonly used immuno-nephelometric methods, a commercial variant of the Clauss clotting rate method, and the classical syneresis method, do not differ significantly using patient material, in the interval 2-12 g/l. A research ELISA method that measures intact fibrinogen is not linearly correlated to the syneresis method. The commutability of available calibrators and reference materials (including the WHO 2nd IS) was only 50-80% except for one of the calibrators for which the virtual concentration coincided with that obtained by the syneresis method.

Nitrated fibrinogen is a biomarker of oxidative stress in venous thromboembolism

“…Fibrinogen levels were also similar between DVT and PE patients irrespective of the assay employed (Clauss: DVT, n=17: 3.8 mg/ml, 95 % CI 3.0–4.6; PE, n=27: 4.5 mg/ml, 95 % CI 3.6–5.4; ELISA: DVT, n=21: 5.5 mg/ml, 4.4–6.5; PE, n=28: 5.6 mg/ml, 4.7–6.5) (Figure 1A). ELISA-determined fibrinogen levels were higher than those reported by Clauss assay, which is consistent with findings in previous studies (21). …”

Harmonization of fibrinogen assay results: study within the framework of the Dutch project ‘Calibration 2000’

“…Commutability is defined as the degree to which a material yields the same numerical relationships between results of measurements by a given set of measurement procedures, purporting to measure the same quantity, as those between the expectations of the relationships for the same procedures applied to those types of material for which the procedures are intended (Miller, 2003). As far as we know, the commutability of lyophilized materials for fibrinogen assays has been investigated in one study only (Kallner et al. , 2003).…”