Cord Blood VWF & FVIII Levels

On Monday, 5-18-26, Stuart Lind, MD, University of Colorado Hospital and School of Medicine, asked, “Would you know of any primary references that validate cord blood levels?” A PubMed search yielded this reference describing VWF levels, available from your medical library: Schneider DM, von Tempelhoff GF, Herrle B, Heilmann L. Maternal and cord blood hemostasis […]

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Coagulation Factors

Apr 25 2026

george

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

FXI and XII Non-parallelism Puzzle

Sacha Uljon, MD, PhD, Medical Director, Core Laboratory, Massachusetts General Hospital, sends us an FXI and FXII puzzle: This is a question for Werfen ACL Top users: We have noticed non-parallelism for FXI and FXII, increasing factor levels with increasing dilutions, even in patients without LAC. We’ve done a lot of troubleshooting; this seems to […]

Factor Assays

Field Study Compares OSA With CSA for Measuring Efanesoctocog Alfa

Here is an open-access article contrasting the validity of OSA versus CSA for measuring efanesoctocog alfa (Altuviiio®) spiked into normal plasma: Pipe S, Sadeghi-Khomami A, Konkle BA, et al. A global comparative field study to evaluate the factor VIII activity of efanesoctocog alfa by one-stage clotting and chromogenic substrate assays at clinical haemostasis laboratories. Haemophilia. […]

Factor Assays

Associations of FVIII & FIX Levels with CVD and CVD Mortality

Go to your medical library to access this provocative journal article: Harris K, Woodward M, Folsom AR, et al. Associations between plasma levels of coagulation factors VIII and IX and incident cardiovascular disease and mortality: systematic review and meta-analysis. J Thromb Haemost. 2025:S1538-7836(25)00598-7. doi: 10.1016/j.jtha.2025.09.008. PMID: 41038279. Abstract Background: Associations of plasma levels of coagulation […]

Arterial Thrombosis

Case Study: Measuring TAT Complex in LVAD Implantation

Check with your library for this article describing the TAT Assay in LVAD Implantation. Ling L, Liu C, Zhou J. Thrombin-antithrombin complex might be a promising parameter for monitoring anticoagulation in the early postoperative period after LVAD implantation. Lab Med. 2025 ;56:423–7. doi: 10.1093/labmed/lmae113. PMID: 40085520. Abstract Introduction: Appropriate bridging anticoagulation is critical in the […]

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Anticoagulant Therapy

Jul 26 2025

george

Status of Gene-based Hemophilia A and B Therapy

Click here for an open-access, in-depth, illustrated review of the worldwide status of gene-based HA and HB therapy: Glasner MF, Pipe S, Miesbach W. Gene-based therapies for hemophilia. Res Pract Thromb Haemost. 2025;9:102870. doi: 10.1016/j.rpth.2025.102870. PMID: 40488175; PMCID: PMC12143782.

Bleeding Disorders

May 2025 QQ Summary: Terminology

Our May 2025 Quick Question was meant to be a brain teaser inspired by Dave McGlasson’s December 2023 Clot Club entry, “Do We Need to Standardize Coagulation Nomenclature in Today’s Laboratory Environment?” The question listed several assays that use the letter C. “Which is the routine assay for inflammation?” It seems that only four of […]

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Quick Question Archive

May 27 2025

george

Bovine Chromogenic FVIII Recovery

Click here to read a poster presented at ISLH: Quinton T, Black KM, Sadeghi-Khomami A. Performance of a Novel Bovine Chromogenic Factor VIII Assay in the Recovery of Factor VIII Replacement Therapies. ISLH 2025. The investigators report the efficacy of a chromogenic substrate FVIII assay that employs bovine reagents on several FVIII therapeutics in current use.

Factor Assays

FVIII-Depleted Reagent Plasma With and Without VWF

The poster, Henneberry S, Rahman M,Wood A, Notini KM, Black KM, Sadeghi-Khomami A. Comparative analysis of commercial factor VIII (FVIII) deficient plasmas with and without von Willebrand factor for FVIII one-stage clotting assay (OSA) was presented on Thursday, 8 May 2025 at the ISLH meeting in Halifax, NS. Click here to see the poster.

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Bleeding Disorders

Factor Assays

Cord Blood VWF & FVIII Levels

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

FXI and XII Non-parallelism Puzzle

Field Study Compares OSA With CSA for Measuring Efanesoctocog Alfa

Associations of FVIII & FIX Levels with CVD and CVD Mortality

Case Study: Measuring TAT Complex in LVAD Implantation

Status of Gene-based Hemophilia A and B Therapy

May 2025 QQ Summary: Terminology

Bovine Chromogenic FVIII Recovery

FVIII-Depleted Reagent Plasma With and Without VWF

George Fritsma MS MLS

Cheat Sheets from George

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