All Posts

The PFA-100/200

I (Geo) received these questions from Brenda Goforth on 12/19/24 and received assistance from colleague and coagulation expert David McGlasson in locating relevant research documents: I have two questions regarding the interpretation of PFA-100 closure times (CTs): 1. If the CT results are below (shorter than) the normal reference range, would this still be considered […]

Platelet Function Testing

Pfizer’s Hympavzi® (marstacimab) Anti-TFPI Approved

The first of the anticipated “rebalancing” therapies, Pfizer’s marstacimab (Hympavzi®), an anti-TFPI recombinant monoclonal antibody, was approved by the FDA in October 2024 for use in hemophilia A and B patients without inhibitors. Click here for the AJMC news release (American Journal of Managed Care).

Bleeding Disorders

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.

More on Altuviiio Assays

This post with its dialogue between Dr. Uljon and Dr. Sadeghi-Khomami describes how to minimize EHL measurement discrepancies. Read to the end! Here’s a post from Sacha N. Uljon MD PhD, Massachusetts General Hospital (MGH) and Brigham and Women’s Hospital (BWH), Boston, US, describing their experience with Altuviiio measurement using a one-stage clot-based assay and […]

Bleeding Disorders

December 2024 Cheat Sheet

Click here to receive your December 2024 Cheat Sheet. If you would like to join the list of participants who receive their monthly Cheat Sheet via email, please complete the brief form on the home page. The Cheat Sheet and your partnership with Fritsma Factor are free.

November 2024 QQ: Cryoprecipitate

Our November 2024 Quick Question, which attracted 28 responses, asked, “Who invented cryoprecipitate?” Dr. E. J. Kohn: 1 (4%) Dr. Judith Pool: 19 (68%) Dr. Armand Quick: 3 (11%) Dr. Rudolph Virchow: 4 (13%) Dr. Kenneth Brinhous: 1 (4%) Comments: Cryoprecipitate (Cryo) was developed and produced by Judith Pool, PhD, 1919–1975, from Stanford University in […]

Quick Question Archive

Clot Detection in Whole Blood Specimens

I (Geo) received this message on 11-27-24 from Dr. Ludwig Albornoz: After a simple search on Google, we landed on your website, regarding a practice of detecting and removing fibrin and or blood clots in clinical laboratory blood specimens by using a mechanical method, either plastic or wooden rods, which I introduced for use in […]

Specimen Management

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

Coag Conversation: ITP and Platelet Functional Disorders, Part 2

Here is the second of our three-part series, “A Coag Conversation: ITP and Inherited Platelet Function Disorders.” featuring Michele Lambert, MD, MSTR, interviewed by George Fritsma and sponsored by BioMedica Diagnostics, Inc. Dr. Lambert is Associate Professor of Pediatrics at the Pearlman School of Medicine, University of Pennsylvania and Pediatric Hematologist at the Children’s Hospital […]

Platelet Function Testing

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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.

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