Anticoagulant Therapy

Jan, 2021 QQ: The Chromogenic Factor X Assay

Before 2010, several articles were published supporting the chromogenic factor X [CFX] assay [not to be confused with the chromogenic anti-factor Xa heparin assay] for monitoring warfarin therapy, especially in patients whose lupus anticoagulant [LAC} could falsely prolong the prothrombin time. Two of these articles are attached below. While the data published made it clear […]

Anticoagulant Therapy

DOAC-STOP In Vitro DOAC Removal and LAC

From Asha Rajai: Is it OK to use DOAC-STOP for lupus testing? Has it been approved by ISTH or CLSI? Hello, Asha. Yes, DOAC-STOP [DiaPharma] and DOAC-Remove [Aniara] effectively absorb dabigatran, rivaroxaban, or apixaban from specimens that are submitted for lupus anticoagulant [LAC] testing, allowing for accurate PTT– and DRVVT-based screen and confirm assays for […]

Anticoagulant Therapy

Warfarin and Cannabis

Thanks to hemostasis expert and colleague Dave McGlasson for a recent phone discussion on the effects of marijuana on warfarin therapy [disclaimer: no personal experience]. A literature search turned up several studies and meta-analyses associating THC with markedly raised INR, implying an effect on the cytochrome oxidase pathway. Click review article Damkier P, Lawwen D, […]

Anticoagulant Therapy

In vitro detection and removal of DOACs from patient plasma specimens

Announcing a 9-30-20 open access publication [forgive the self-reference]: McGlasson DL, Fritsma, GA. In vitro detection and removal of direct oral anticoagulants from patient plasma specimens. Annals of Blood 2020:doi: 10.21037/aob-20-16. We describe a urine DOAC Dipstick and several competing “filter” devices that remove DOACs from plasma, enabling the operator to perform clot-based [PT and […]

Anticoagulant Therapy

Apixaban Assay Approved

On 9-22-20, Instrumentation Laboratory, A Werfen Company, received US FDA de novo approval for their automated chromogenic HemosIL® Liquid Anti-Xa test kit to measure apixaban [Eliquis]. Click here for IL‘s press release.

Anticoagulant Therapy

In Vitro DOAC ID and Removal

We reported on the DOAC-Dipstick®, and four in vitro devices designed to remove interfering DOACs from specimens prepared for clot-based and chromogenic substrate assays in our 9-30-20 article [click], McGlasson DL, Fritsma GA. In vitro detection and removal of direct oral anticoagulants from patient plasma specimens. Annals of Blood 9-30-20; doi: 10.21037/aob-20-16. These devices are […]

Anticoagulant Therapy

Covid-Coag Conversation Video

Thanks to all who participated in our September 15, 2020 webinar, “COVID-Associated Coagulopathy: A Conversation about the Controversies & Confusion” [click] featuring Dr. Andrew Goodwin, University of Vermont Medical Center. Click the title line if you would like to view the webinar again or if you did not have the opportunity to attend the live […]

Anticoagulant Therapy

Dilute Thrombin Time

From Deanna Miller, Children’s Hospital of Alabama. Do you have any good references for diluted thrombin and utilization of this test? What dilution is best? 1:1 or 1:3? Hello, Deanna, and thank you for your question. We use the plasma-diluted thrombin time to measure the direct thrombin inhibitors [DTIs] dabigatran, argatroban, or bivalirudin. The assay […]

Anticoagulant Therapy

What is Osocimab?

The first phase 2 antithrombotic efficacy and safety results for the novel anti-activated coagulation factor XI [anti-XIa] monoclonal antibody are reported in Weitz JI, Bauersachs R, Becker B, et al. Effect of osocimab in preventing venous thromboembolism among patients undergoing knee arthroplasty; The FOXTROT randomized clinical trial JAMA. 2020;323:130–9. doi:10.1001/jama.2019.20687. This is an exciting new approach […]

Anticoagulant Therapy

Can Heparin Prevent Covid?

Thanks to George’s colleague Rodney Rohde, PhD, Texas State University, who posted this Contagion Live article by Grant M. Gallagher on LinkedIn entitled FDA-Approved Anticoagulant May Stop Coronavirus From Binding to Human Cells [click or tap]. This is a suprising and apparently authentic description of a non-antithrombotic Covid-preventative property of heparin, separate from heparin’s prophylactic […]

Anticoagulant Therapy

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George Fritsma is a medical laboratory scientist, educator, and author. George holds faculty appointments with Rutgers University and Michigan State University, and is a member of the International Society on Thrombosis and Hemostasis, American Association of Clinical Chemists, and American Society for Clinical Laboratory Science.

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