Abstract Number: PB0060
Meeting: ISTH 2021 Congress
Background: Heparins are a class of anticoagulant drugs that are used to prevent and treat thrombosis. The most effective way of monitoring heparin therapy is through anti-Xa assays; these are important to ensure clinical effectiveness and reduce the risk of over-anticoagulation.1 Inclusion or exclusion of dextran sulfate (DS) in heparin assay reagents impacts measured unfractionated heparin (UFH) levels. The purpose of including DS in reagents is to increase stability and prevent false-low heparin results due to the binding of non-specific proteins to heparin in vivo.2 However, reagents that include DS may overestimate the in vivo heparin level.3
Aims: To investigate the impact of dextran sulfate in heparin monitoring reagents on external quality assessment (EQA) results.
Methods: Data from RCPAQAP’s heparin monitoring surveys was analysed, including comparing the median of all participants to the medians of our 3 largest reagent groups: Siemens INNOVANCE heparin, HemosIL Liquid Anti-Xa, and Stago STA-Liquid Anti-Xa.
Results: Siemens INNOVANCE heparin and HemosIL Liquid Anti-Xa include dextran sulfate, while Stago STA-Liquid Anti-Xa does not.2 Inclusion of DS promotes stability and releases heparin from Platelet Factor 4 complexes, establishing free (and active) heparin. However, not all protein-bound heparin is active in vitro, therefore addition of DS may overestimate functional heparin.3
As seen in Figure 1, Siemens INNOVANCE heparin and HemosIL Liquid Anti-Xa, the reagents that include DS have increased median UFH results compared to Stago STA-Liquid Anti-Xa which does not include DS.
The differences between DS including and excluding reagents may be reduced in EQA reports such as RCPAQAP’s since dextran is added as a stabilising excipient, and the process of lyophilising can have an impact.1
Conclusions: RCPAQAP’s heparin monitoring survey data aligns with manufacturers data, where it has been found that heparin reagents that include dextran sulfate have increased anti-Xa results compared to reagents that exclude it.
To cite this abstract in AMA style:Dean E. The Effect of Dextran Sulfate in Heparin Monitoring Reagents [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/the-effect-of-dextran-sulfate-in-heparin-monitoring-reagents/. Accessed September 21, 2023.
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