“Covid Coag”

On May 26, I (Geo) posted a link to our informational module, The Cell-based Coagulation Model. On May 15, I posted a link to our Coagulation Overview Module. The third in a series of “Mechanism” modules, and perhaps the most complex, is entitled Covid Coag. Though thanks to vaccination technology, we think less today about […]

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Bleeding Disorders

May 28 2026

george

A Treasure Trove of VWD Articles

The May 2026 issue of Seminars in Thrombosis and Hemostasis provides a “mother lode” of open-access VWD articles in observance of Dr. Erik von Willebrand‘s 1926 article, Hereditar Pseudohaemophili, now 100 YOA. Check with your medical library for Nilsson IM. Commentary to Erik von Willebrand’s original paper in Haemophilia. 1999;5:220-1. doi: 10.1046/j.1365-2516.1999.0320a.x. PMID: 10444292 (no […]

Bleeding Disorders

Aspirin Prophylaxis

The question appeared on the Diagnostic Equity site, paraphrased with the approval of site proprietor Tamara Lobban-Jones: “I’ve heard that some people take a ‘ton of baby aspirin.’ My doc told me to take only one a day. Does taking multiple tablets help with clotting? What does taking one aspirin do to the blood, and […]

Antiplatelet Therapy

VWD Test Panel: A Correction

Thanks to Dr. Emmanuel Favaloro for pointing out an error in our April 29 post, “Quick Question Results, VWF Activity.” I (Geo) had transposed the principles of the VWF:GP1bR and VWF:GP1bM. I’ve corrected the error in the April 29 post–the correct principles are that VWF:GP1bR employs ristocetin, whereas VWF:GP1bM employs a gain-of-function form of GP1b […]

Bleeding Disorders

April 2026 QQ Results: VWF Activity

Our April 2026 Quick Question reprises our 2023 QQ that asked, How do you measure VWF activity. Our 29 respondents answered as follows: VWF:RCo: 16 (56%) VWF:GP1bR: 6 (21%) VWF:GP1bM: 5 (16%) VWF:CB: 2 (7%) RIPA: 0 Our 4-1-2026 introductory QQ post attracted this comment from Dr. Emmanual Favaloro, Sydney, NSW, Australia: Hi George, of course, […]

Bleeding Disorders

A Comparison of The Clauss Fibrinogen Assay with the Prothrombin Time-derived Assay

Click here for an open-access 2026 article comparing the time-honored Clauss fibrinogen assay with the PT-derived assay: Latona A, Hill K, Rane M, Ho A, Mitra B. Diagnostic accuracy of Clauss and prothrombin time-derived fibrinogen against rotational thromboelastometry FIBTEM-A5. Res Pract Thromb Haemost. 20266;10:103439. doi: 10.1016/j.rpth.2026.103439. PMID: 42027315; PMCID: PMC13100266. Abstract Background: Fibrinogen levels may […]

Factor Assays

How to Identify PK or HMWK Deficiency

Here is a paraphrase of a question I (Geo) received on 4-3-26: “We recently evaluated a patient with an isolated prolonged APTT that corrected on mixing study. The patient has no history of bleeding and no significant family history of bleeding disorders. FVIII, FIX, FXI, and FXII assays were within normal limits. In view of […]

Bleeding Disorders

Case Study: VWF Inhibitors in Brothers

This open-access article describes inhibitor formation in two brothers who were subjects in a Wilate® study: Djambas Khayat C, Pavlova A, Werner S, Knaub S, Sidonio RF Jr. von Willebrand factor (VWF) inhibitors in two brothers with von Willebrand disease: a case report. TH Open. 2025;9:a26069625. doi: 10.1055/a-2606-9625. PMID: 40673043; PMCID: PMC12265396. Abstract The development […]

Bleeding Disorders

Meta-analysis: BAT in VWD Dx

At the March 18–21, 2026 THSNA meeting in Portland, Oregon, USA, there were several oral and poster presentations on VWD symptoms, management, and laboratory diagnosis and monitoring. Here is an open-access meta-analysis on BAT efficacy in VWD: Kalot MA, Husainat N, Tayiem S, et al. Bleeding assessment tools in the diagnosis of VWD in adults […]

Bleeding Disorders

Effects of Platelet Transfusions on Neonates

Check your medical library for this article that describes levels of morbidity and mortality of neonates receiving platelet transfusions: Davenport P, Feldman HA, Young V, et al. Effects of platelet transfusions on neonatal bleeding and inflammation. Pediatr Res. 2025 Nov 5. doi: 10.1038/s41390-025-04498-9. Erratum in: Pediatr Res. 2025 Dec 2. doi: 10.1038/s41390-025-04676-9. PMID: 41193819. Abstract […]

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Bleeding Disorders

Bleeding Disorders

“Covid Coag”

A Treasure Trove of VWD Articles

Aspirin Prophylaxis

VWD Test Panel: A Correction

April 2026 QQ Results: VWF Activity

A Comparison of The Clauss Fibrinogen Assay with the Prothrombin Time-derived Assay

How to Identify PK or HMWK Deficiency

Case Study: VWF Inhibitors in Brothers

Meta-analysis: BAT in VWD Dx

Effects of Platelet Transfusions on Neonates

George Fritsma MS MLS

Cheat Sheets from George

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