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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

How to Measure Plasma Efanesoctocog Alfa [Altuviiio]

For those like me (Geo) who are just learning of it, efanesoctocog alfa (Altuviiio™), US FDA-approved in February of 2023 is Sanofi/Sodi’s extended half-life synthetic FVIII concentrate. Here is an edited description of Altuviiio’s structure and PK from the package insert. Altuviiio (efanesoctocog alfa, ehtl, recombinant AHF, Fc–VWF-XTEN fusion protein) replaces missing FVIII needed for […]

Bleeding Disorders

Hemostasis Quality Control Modules

Fritsma Factor is pleased to introduce our most recent audio PowerPoint modules, Hemostasis Quality Control Part 1 and Hemostasis Quality Control Part 2. These modules were produced by friend, colleague, and co-author Mayukh Sarkar, Ph.D MLS [ASCP] for the Rutgers University 2023 graduate course, Advanced Hemostasis CLS5124. Dr. Sarkar has a wealth of QC experience […]

Platelet Satellitism

Here’s a March 11, 2024 message from Erika Knuckles, Hematology Supervisor, Phelps Health. “Good Morning George, I was consulting ‘Mr. Google’ to see if I could find any information on what would cause patients to form platelet clumps in both EDTA and sodium citrate. We excluded the collection process. diseases, and medication. I thought you […]

Specimen Management

Heparin and Mixing Studies

From colleague Brenda Goforth, Senior CLS Hematology, Coagulation, and Urinalysis | Clinical Laboratory, Antelope Valley Medical Center Hi George, When using Hepzyme on patients who are on heparin and a mixing study is ordered, what is the standard for when neutralization is complete? If the PTT is normal after one neutralization, then proceed to 37ºC incubation, but what […]

Still More on Chronically Elevated D-dimer

We’ve received an additional comment on our February 3, 2024 entry on the topic of chronically elevated D-dimer.

More on CaCl2 Validation

We recommend you return to our February 4, 2024 entry that discusses CaCl2 validation. We’ve received additional comments including a comprehensive response from several expert CAP staff members.

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

Quick Question