Influences of argatroban on five fibrinogen assays

Abstract

The influences of argatroban on fibrinogen assays differ greatly, clinicians should be aware of the influences of argatroban on the fibrinogen assays used on site to avoid misdiagnoses.

Guidelines on the laboratory aspects of assays used in haemostasis and thrombosis

“…Fibrinogen sialylation may be increased in neonates and in liver disease which may prolong the TT but does not alter the Clauss assay. High levels of fibrin degradation products (FDPs) or direct thrombin inhibitors (DTI) may inhibit some Clauss assays depending on the thrombin concentration in the reagent, resulting in variable underestimation of fibrinogen concentration 69,83,84 . The Clauss assay is not usually affected by therapeutic levels of heparin although reports of variability in fibrinogen estimation have been reported in cardiac patients on bypass 85…”

Argatroban Treatment and Decreased Fibrinogen in a Septic Patient

“…Their results showed a significant reduction of fibrinogen using the Hemosil Fibrinogen-C XL reagent (Instrumentation Laboratory, Bedford, MA), via the Clauss method on ACL-TOP (P<0.01) based on aPTT ratios. This included a significant reduction of fibrinogen values of up to 96% compared to baseline (P<0.01) [4].…”

“…Argatroban is a parenteral direct thrombin inhibitor that has strong recommendations to be used as an alternative choice for anticoagulation in patients with heparin-induced thrombocytopenia [4]. Supervising its anticoagulant activity is regularly achieved by the aPTT.…”

“…This can lead to clotting time prolongation. Of note, coagulation tests (aPTT, PT, and fibrinogen) are based on the measurements of clotting time [4].…”

Falsely Low Fibrinogen Levels in COVID-19 Patients on Direct Thrombin Inhibitors

“…This problem has been reported on several different commercial platforms with samples containing both bivalirudin and argatroban. 4,5 The Clauss assay in our particular laboratory uses a reagent with the highest commercially available thrombin concentration-100 NIH units (UNIH)/mL (QFA Thrombin, Instrumentation Laboratories, Bedford, MA). Despite this high level, "inhibitors" can still interfere with fibrinogen assessment.…”