Variability in heparin sensitivity of appt reagents in heparinized plasma in vitro and patients receiving heparin

Abstract

Introduction: At the end of the 1980s and at the beginning of the 1990s, several studies showed lack of standardization and variability in APPT results due to the different sensibilities to heparin in reagents used for its determination. Objective: To evaluate the sensibility to heparin in the different reagents used to determine APPT in samples of heparinized plasma in vitro and in patients using non-fractioned heparin (NFH). Material and Methods: This study was performed with a pool of heparinized plasma with concentrations from 0.1 to 1.0 unit heparin/mL, 29 patients using NFH and 8 reagent kits for TTPA determination. Results and Discussion: Using heparinized plasma in vitro, there was a statistically significant difference with Actin® reagent in relation to Labtest®, Human® and Clot® reagents. The best correlation coefficient, a result of the APTT versus UFH concentration was observed with reagent from Stago® (R = 0.9919). When we used the plasma from patients using UFH, the results of Actin ® and Actin FSL® were statistically different from the Clot®.

Keywords

• Tempo de tromboplastina parcial ativado
• Heparina
• Anticoagulantes
• Monitoramento
• Sensibilidade.