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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) […]

May 2024 Cheat Sheet

Here’s your May 2024 Cheat Sheet recounting several April posts and events. If you want to receive our Cheat Sheet in your email, click “Cheat Sheets from George” and provide your first and last name. Like Fritsma Factor, Cheat Sheets are free, and subscribing does not expose you to marketing materials.

May 2024: QQ Poll: Trigger Point for PLT Concentrate Therapy

Our May 2024 Quick Question asks, “Below what PLT count limit do you provide PLT concentrate?” Please show us your facility’s PLT count limit and add a comment below or using the Questions or Comments box.

Bleeding Disorders

April 2024 QQ Summary: MYH9 Mutation

Our April 2024 Quick Question, “What PLT production abnormality is an MYH9 gene mutation?” attracted 26 responses. Here’s the distribution: Thrombocytopenia with absent radii [TAR]: 4 [15%] Bernard-Soulier syndrome [BSS]: 2 [7%] Immune thrombocytopenia [ITP]: 1 [4%] Wiskott-Aldrich syndrome: 1 [4%] May-Hegglin disorder: 18 [70%] The production abnormalities are associated with mild to severe bleeding. […]

Bleeding Disorders

Testing for the Lupus Anticoagulant: The Good, the Bad, and the Ugly

Click here for a “State of the Art Review,” Favaloro EJ, Pasalic L, Selby R. Testing for the lupus anticoagulant: The good, the bad, and the ugly. Research and Practice in Thrombosis and Haemostasis 2024; 8: DOI:https://doi.org/10.1016/j.rpth.2024.102385.

VWD Diagnosis and Monitoring Update

Dr. Annette Bowyer posted this open-access publication today, 3-3-24 on LinkedIn: Platton S, Baker P, Bowyer A, et al. Guideline for laboratory diagnosis and monitoring of von Willebrand disease: A joint guideline from the United Kingdom Haemophilia Centre Doctors’ Organisation and the British Society for Haematology. Br J Haematol. 2024 Mar 26. doi: 10.1111/bjh.19385. Epub […]

Bleeding Disorders

April 2024 Cheat Sheet

Click here for your April 2024 Cheat Sheet or watch for your copy by email.

April 2024 QQ: MYH9 Mutation

Molecular diagnostic methods have defined scores of platelet disorders that by phenotype alone were categorized as production or functional disorders. Our April 2024 Quick Question is a quiz that “scratches the surface” by asking what disorder or syndrome is part of the MYH9 gene mutation family. For a look at molecular diagnostics practical applications, see […]

Platelet Function Testing

March 2024 Quick Question Summary: Factor Deficiency

Our March 2024 Quick Question was a quiz. The question was, “What factor deficiency causes bleeding but doesn’t prolong the PT or PTT?” Our 75 respondents answered as follows: FVIII: 7 [9%] FIX: 3 [4%] FXI: 3 [4%] FXII: 8 [11%] FXIII: 54 [72%] Factor VIII, IX, XI, and XII deficiencies prolong the PTT but […]

Bleeding Disorders

Establishing the PTT-based UFH Therapeutic Range

A March 22 entry from Robyn Coleman, Senior Scientist, Coagulation, Haematology, Sullivan Nicolaides Pathology, Queensland, Australia: Dear George, I am seeking some direction on APTT therapeutic ranges for UFH. We are facing a change to our APTT reagent. The cohort of patients we would have traditionally used to validate UFH therapeutic range (TR) for APTT, […]

Anticoagulant Therapy

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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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