RESUMO
Argatroban is indicated in the management of patients with suspicion of Heparin-Induced Thrombocytopenia. Biological monitoring of argatroban can be carried out using the activated partial thromboplastin time (APTT) or the measurement of the anti-IIa activity. However, APTT is susceptible to many interferences making its use unsuitable. The objective of this work is to define and verify the performance of a dosing protocol for the anti-IIa activity of the argatroban from the STA ECA-II reagent (Diagnostica Stago) and compare them to the Hemoclot Thrombin Inhibitor proposed by Hyphen Biomed based on diluted thrombin time. Calibration curve shows a good correlation between anti-IIa activity and the coloration level of the reaction medium over the concentration range studied (0 to 2 µg/mL). The analytical performances obtained at the native dilution of 1/10th are excellent, both in terms of repeatability and reproducibility with a coefficient of variation below 10%. Automatic relaunch at 1/20th for sample concentrations greater than 2 µg/mL does not impact this performance level. We obtain a limit of quantification below 0.2 µg/mL. The comparison of the methods gave consistent and well-correlated results on a wide range of concentrations (0.3 to 4 µg/mL). The use of the STA ECA-II reagent is a valuable alternative to APTT for biological monitoring of anticoagulant action of argatroban.