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August 2024 Quick Question: Hemophilia Treatment

Several hemophilia A or B treatments are in development or have been approved since 2021. Among these are the “rebalancing” preparations that suppress control proteins such as tissue factor pathway inhibitor (TFPI), antithrombin (AT), or activated protein C (APC). Rebalancing preparations are designed to compensate for the bleeding tendencies in FVIII or FIX deficiency without […]

Bleeding Disorders

July 2024 Quick Question: Specimen Storage

Our July 2024 Quick Question, which drew 58 responses, asked, “How long may you store a specimen after collection for a PT test?” Our answers were: 1 hr: 2 (3%) 4 hrs: 19 (33%) 8 hrs: 7 (12%) 24 hrs: 30 (52%, the correct answer) This question draws attention to the March 2024 publication of […]

Quick Question Archive

Low Titer Group O Whole Blood in Trauma

Click here for a July 2024 CAP Today article describing the growing use of low titer group O whole blood in trauma and emergencies and its effect on trauma-induced coagulopathy.

Bleeding Disorders

Bioengineered FVIII: efanestocog alfa

Here is a richly illustrated open-access editorial of the development and physiologic function of efanesoctocog alfa (Altuviiio®, Sanofi), which features a half-life 4X that of current concentrates: Chowdary P. Bioengineered factor VIII–more innovation for Hemophilia A. N Engl J Med. 2024;391:277–82. doi: 10.1056/NEJMe2313795. PMID: 39018538.

Bleeding Disorders

Concizumab, A “Rebalancing Agent”

Below is the abstract of a 2019 presentation by Amy Shapiro MD, CEO and co-medical director of the Indiana Hemophilia & Thrombosis Center in Indianapolis, Indiana, USA, describing the rebalancing agent concizumab, approved as Alhemo® by Health Canada in March 2023 but rejected by the US FDA on May 5, 2023, with a request for […]

Bleeding Disorders

Fitusiran: A “Rebalancing Agent”

Fitusiran is an inhibitory double-stranded RNA (RNAi, also called small interfering RNA, siRNA). Fitusiran, termed a “rebalancing agent,” suppresses the nuclear production of antithrombin (AT) messenger RNA (mRNA). AT is a major coagulation control protein that binds and disables thrombin and FXa (also FIXa and FXIa to a lesser extent). By suppressing AT production, fitusiran […]

Bleeding Disorders

Your July, 2024 Cheat Sheet

Click here to download your July 2024 Fritsma Factor Cheat Sheet and also watch for your copy in your email this week. The Cheat Sheet provides links to our June 2024 activities.

July 2024 QQ: Specimen Storage

Coag specimen mismanagement is the source of most errors in hemostasis testing. As mentioned in our June 28, 2024 entry, Adjusting AC Volume in Polycythemia, CLSI released its latest edition of H21: Collection, Transport, and Processing of Blood Specimens for Testing Plasma-Based Coagulation Assays, 6th ed. Guideline H21, Clinical Laboratory and Standards Institute, 2024. The […]

Specimen Management

June 2024 QQ Poll Summary: OSA and Chromogenics

Our June 2024 Quick Question attracted 18 responses. This month’s Question was a poll that asked, “How do you assay factor concentrates?” Here are our answers: Clot-based assay: 11 [61%] Chromogenic substrate assay: 4 [22%] Other: 3 [17%] Factor assays are most often requested to monitor hemophilia factor concentrate activity for patient-specific efficacy and the […]

Adjusting AC Volume in Polycythemia

University of Alabama at Birmingham clinical pathologist Chad Siniard MD, shared the following streamlined approach to adjusting the sodium citrate volume to accommodate specimens from patients whose hematocrit exceeds 55%. The formula is adapted from CLSI Collection, Transport, and Processing of Blood Specimens for Testing Plasma-Based Coagulation Assays, 6th ed. Guideline H21, Clinical Laboratory and […]

Specimen Management

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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.

Cheat Sheets from George

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