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Annals of Blood Author Interview

The 2018 article, Ernst DJ, Fritsma GA, McGlasson DM. Labeling tubes before collection threatens patient safety, 2018 Annals of Blood, doi: 10.21037/aob.2018.02.06 earned the journal’s Readers’ Choice Award for being accessed more than 20,000 times. AOB Editor Jin Ye Yeo invited me (Geo) to provide a written interview, released on December 18, 2024. Thanks to […]

Medical Laboratory Science Career Pathway

This post is a departure from our hemostasis focus. I (Geo) am a Medical Laboratory Scientist practitioner and educator. If you wish to apply your science knowledge to a humanitarian career, consider our profession. On December 6, 2024, ASCP’s Am J Clin Pathol published Guenther GA, Shahrir SF, Skillman SM, Kundu I, Garcia E, Frogner […]

NBA: Why 50%?

From Barbara Schmidtz BSA, MSc, MLT, Regina General Hospital, Sask Health Authority (SHA), 12/6/2024: Hi, I found your page while googling. I’m an MLT in a hospital lab. I was wondering if you could tell me why Bethesda titers are read at 50% residual activity. I understand the curve is linear from 25-75%, but I […]

Conference Calendar

With thanks to Elaine Benoit, Precision BioLogic Inc., we’ve recently updated our Conference Calendar, which lists the major international hemostasis and laboratory medicine-related conventions. Please review the list for the latest information. Contact George if you would like to add your 2025 conference.

Clot Club: Hemophilia Therapy

on 11/13/2024, Fritsma Factor colleague Dave McGlasson, Clot Club contributor, posted Extended Half-life (EHL) Testing for Factor VIII (FVIII) and Factor IX (FIX) Therapies. His entry provides comprehensive laboratory assay information for managing all current factor concentrates and bypassing therapies.

Bleeding Disorders

Lupus Anticoagulant Testing

Anfal Helu asked: I have a question regarding the screening and confirmatory testing for the lupus anticoagulant (LA). Recently, a young female pt was clotting everywhere after a hospital visit for a status epilepticus attack during which she was intubated and placed on mechanical ventilation. She had 2 pulmonary emboli, 2 MI, ischemic colitis, renal […]

FVIII Level and Inhibitor Studies

From Chad Siniard, MD, University of Alabama at Birmingham (UAB) Hospital Laboratory Medicine. George, We have a FVIII activity level that is exactly 30%. We haven’t documented an official level for triggering an inhibitor titer, though our coag lab scientist Laura Taylor customarily runs an inhibitor assay if the result is <30%. We assayed using […]

September 2024 Quick Question: PTT

I (Geo) prefer PTT to APTT or aPTT because the “A” or “a” is superfluous. Laboratory scientists no longer offer an “unactivated” PTT. The “partial thromboplastin” reagent consists of a phospholipid or combination of phospholipids that may include animal, plant, or synthetic sourced phosphatidylserine, phosphatidylcholine, phosphatidylinositol, sphingomyelin, and/or phosphatidylethanolamine. Accompanying the phospholipid is one of […]

Is DRVVT Normalization Necessary?

The clot-based dilute Russell viper venom test (DRVVT) reagent activates the coagulation mechanism’s common pathway at the factor X (10) level, relying only on factor V, prothrombin, and fibrinogen for clot formation. The DRVVT test complements the PTT-based assay for lupus anticoagulant (LAC) detection. Because LAC is phospholipid (PL)-dependent, both assays use a minimal-phospholipid (PL) […]

March 2024 Cheat Sheet

Click here for our March 2024 Cheat Sheet or watch for yours in your inbox next week.

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George Fritsma is a medical laboratory scientist, educator, and author. George is a member of the International Society on Thrombosis and Hemostasis, the International Society for Laboratory Hematology, and the American Society for Clinical Laboratory Science.

Cheat Sheets from George

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