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Lab Assessment of FVIII Inhibitors

Click here for an open-access article describing the need for factor inhibitor assessment: Favaloro EJ, Curnow J, Pasalic L. Laboratory assessment of factor VIII inhibitors: when is it required? A perspective informed by local practice. J Clin Med. 2024;14:13. doi: 10.3390/jcm14010013. PMID: 39797095; PMCID: PMC11720995. See also our factor inhibitor discussions under the Bleeding Disorders heading.

Bleeding Disorders

Neutrophil Extracellular Traps

Neutrophil extracellular trap (NET) research has gained prominence beginning in perhaps 2010. I’ve attached an open-access review that illustrates NETs’ functions and shows how NETs connect neutrophils with hemostasis. The article also documents how NETs participate in the process of thrombosis. Click to download Huang G, Wu H, Lin B, et al. Targeting neutrophil extracellular […]

Mixing Studies

From time to time I (Geo) get questions about mixing studies. Click here to access a series of past entries that are compiled in our Mixing Study category. Additionally, click on “Coagulation Mixing Studies” for my 30-minute narrated PowerPoint presentation.

When Do We Titer Inhibitors?

Dana Carton asks, “We currently test for factor inhibitors using the clot-based Bethesda titer as well as a chromogenic bovine assay for Hemlibra patients no matter what the factor level. We recently learned that colleagues don’t look for that inhibitor unless the factor level is less than 5%. Is this a common practice, and would […]

Indirect Reference Interval Determination

Sarkar MK, Fritsma GA, Chapter 3, Quality Assurance in Hematology Testing; Keohane EM, Butina MM, Mirza KM, Walenga JM. Rodak’s Hematology: Clinical Principles and Applications Edition 7 states the following: “Indirect RIs may be derived from stored patient data. The QC specialist mines the laboratory database to compute the mean and confidence interval. Indirect RI […]

Video: Have We Cured Hemophilia?

Click here to view my (Geo) video, Have We Cured Hemophilia?, recorded with Professors Malissa Norfolk and David Cabral as part of their series, Differential Discussions. Part One reviews the history of hemophilia management from the time the first antihemophilic factor was produced to 2014 when turned to the extended half-life hemophilia concentrates.

Bleeding Disorders

Manual Tilt Tube PT

Here is an open-access editorial commenting on the tilt-tube PT requirement for establishing the reagent thromboplastin ISI. Favaloro EJ. Manual tilt tube method for prothrombin time: a commentary on contemporary relevance. Clin Chem Lab Med. 2025;63:1239–42. doi: 10.1515/cclm-2025-0157. PMID: 39985393.

Screening Assays

Inaccuracies of Venous Thromboembolism Risk Assessment

This April 2025 article indicates a ~29% under-reporting of VTE risk in a cohort of medically ill patients: Lau B, Bhave A, Yui JC, et al. Inaccuracies of venous thromboembolism risk assessment and prevention practices among medically ill patients. Blood Adv. 2025:bloodadvances.2024015306. doi: 10.1182/bloodadvances.2024015306. Epub ahead of print. PMID: 40408310.

Updated DIC Parameters from ISTH

The ISTH SSC Subcommittee on Disseminated Intravascular Coagulation has published its latest definition and scoring system for DIC. Click below for the open-access article. Iba T, Levy JH, Maier CL, et al. Updated definition and scoring of disseminated intravascular coagulation in 2025: communication from the ISTH SSC Subcommittee on Disseminated Intravascular Coagulation. J Thromb Haemost. […]

Bleeding Disorders

What is PITT?

Click below for an open-access article that classifies VITT and HIT as members of a platelet factor 4 (PF4) disorder, anti-PF4 mediated thrombocytopenia and thrombosis (PITT). Nicolson PLR, Montague SJ, Buka RJ, et al. Anti-PF4 mediated thrombocytopenia and thrombosis associated with acute cytomegalovirus infection displays both HIT-like and VITT-like characteristics. Br J Haematol. 2025. doi: […]

Arterial Thrombosis

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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.

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