Thrombophilia

Thrombophilia Guidelines

From Mohamed Bashir, originally posted November 17, 2012: What is the guideline for thrombophilia testing, how to test antithrombin (AT, antithrombin III, ATIII), protein C (PC), and protein S (PS). Hello, Dr. Mohamed Bashir, and thank you for your question. You may find a complete review of thrombosis risk testing in our audio modules 14, 15, […]

MTHFR Double Heterozygote?

A question from a colleague: My relative is 35 and is currently about 20 weeks pregnant. She has 2 healthy children, but has also had two miscarriages in the past three years. She is a double heterozygote for MTHFR C677T and A1298C. If I am interpreting the literature correctly, the double heterozygosity should not increase […]

APCR Screening: Everyone?

Our recent series of discussions and comments on the efficacy of D-dimer results in superficial thrombophlebitis for factor V Leiden (FVL) mutation patients has pointed us to a thoughtful discussion of the value of screening unselected populations for activated protein C resistance (APCR), the condition that correlates closely with FVL. Dr. Emmanual Favaloro’s current article; Favaloro EJ, McDonald D. Futility […]

Screening Assays

D-dimer Efficacy in Factor V Leiden Mutation

This 6/30/2012 question from a physician arrived through the American Society for Clinical Laboratory Science Consumer Web Forum. “Does delayed fibrinolysis in a known factor V Leiden (FVL) mutation patient reduce the value of a negative D-dimer test?” George’s initial response: Thank you for your question. I was prepared to answer that there is no connection, […]

How Long Does HIT Ab Remain?

In the comments section of our

Anticoagulant Therapy

HIT Kits

From Ginger Weeden, MLS (ASCP)cm, Bio-Rad Laboratories: George, What heparin-induced thrombocytopenia with thrombosis (HIT) testing is available in the US? I’m wondering how many manufacturers there are. Thanks for any information. Hi, Ginger, and thanks for your question. All the C14 serotonin release assay methods (washed platelets) available from reference labs are laboratory-developed tests. Here are the manufacturers I […]

Anticoagulant Therapy

Serotonin Release by Immunoassay?

Dear George, For heparin-induced thrombocytopenia (HIT) serotonin release assay, can serotonin ELISA sensitive to HIT be used? With regards, Vilas Hiremath. Hello, Vilas, always good to hear from you. I had to go to experts, Drs Larry Brace, Edward Hospital in Naperville IL, and Jon Geske, Precision BioLogic Manager of Emerging Technologies & Markets. Here is a reply […]

Anticoagulant Therapy

Clot-based Protein S Dilutions

From Lisa Reid-Fifoot, Technical Service Manager at Precision BioLogic: I am acquainted with an institution that performs several dilutions on the patient’s sample (1/5, 1/10, 1/20, 1/40, 1/80, 1/160) when performing the clottable protein S (PS) assay. They find they are not getting good agreement amongst all the dilutions especially with low results. I have not […]

Does Beta2-GP1 Affect the SRA?

Here is a question from my colleague Dr. Jeanine Walenga at Loyola University Medical Center in Chicago: Dear George, Is there data on whether beta-2-glycoprotein 1 (β2GP1) interferes in the serotonin release assay (SRA) for heparin-induced thrombocytopenia (HIT) testing? Hello, Jeanine, and thank you for your question, which drove me to the books, PubMed, and ultimately to Dr. […]

Clottable Protein C & S Assays

From Pam Owens at Tricore: We have a specimen from a pregnant patient with a low clottable protein C. Her INR is normal, but she is a heterozygote for both factor V Leiden mutation and the prothrombin 20120 gene mutation. Could the prothrombin gene mutation be interfering with the assay, causing the PC levels to appear lower than they actually […]

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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.

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