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Lupus Anticoagulant and Factor XI

Here is a message from Carol Houde of Emerson Hospital: I’m interested in the association between elevated factor XI activity and the lupus anticoagulant. When doing dilutions how do you effectively differentiate between the “lupus effect” on this PTT-based assay (especially when the LA result is borderline positive)? Hi, Carol. Sorry to say, I know […]

Prekallikrein Assay

A question from Delphine in France about prekallikrein (PK, Fletcher factor) deficiency measurement: is there a difference between the PTT with kaolin versus silica to measure PK deficiency? What is the impact of incubation time? It seems PTT with kaolin doesn’t work well to measure PK? Hi, Delphine. I checked your question with Lynn Quarles […]

QQ Summary: Lupus Anticoagulant Testing

Our participants apparently support some of the principles of the controversial new ISTH lupus anticoagulant testing guidelines; Pengo V, Tripodi A, Reber G, et al. Update of the guidelines for lupus anticoagulant detection. J Thromb Haemost 2009; 7: 1737-40. Here are the answers for our October Quick Question: “The ISTH Scientific and Standardization Committee has issued […]

Quest Diagnostics Symposium March 17-19

Quest Diagnostics and Nichols Institute have just announced their March 17-19, 2010Case Oriented Thrombosis and Bleeding Symposium at the Hyatt Regency, Reston; Reston, VA.

Factor P

From Stacy at the University of North Dakota: George, Can you tell me about Factor P? Stacy Stacy, I believe factor P is a name for properdin, the triggering molecule of the alternate complement pathway. I don’t know much about properdin, but if you have a follow-up question, I’ll be happy to take a shot […]

Ecarin Clot Time

Here is a note about the ecarin time from Twyla Bader: George, how commonly is the ecarin time being used to monitor hirudin during surgery? Also is there any device that performs this superior compared to others? Thank you, Twyla Bader Hello, Twyla, thanks for the question. The ecarin time uses venom from Echis carinatus […]

Hemophilia Therapy: Rasputin to Recombinants

I will present “Hemophilia Therapy: Rasputin to Recombinants” at the Northeast Laboratory Conference, Thursday, October 22, 1:30-3:00 PM at the Portland Holiday Inn by the Bay, Portland, Maine. My talk includes an overview of hemophilia inheritance, pathology, treatment and factor inhibitors. It then moves to hemophilia history including the story of Tsarovich Alexis of Russia, […]

Does Aspirin Work? Presentation Handout

I will present “Does Aspirin Work?” at the Northeast Laboratory Conference, Wednesday, October 21, 10-11:30 AM at the Portland Holiday Inn by the Bay, Portland, Maine. My talk includes a discussion of clinical efficacy for aspirin, clopidogrel (Plavix), and the newly release Eli Lilly antiplatelet drug prasugrel (Effient). We’ll discuss means for detecting and resolving […]

Saliva-based CYP2C19 Screen for Clopidogrel Resistance

In an October 7, 2009 press release, Quest Diagnostics, Inc now offers a saliva-based rapid PCR screen for the cytochrome oxidase P450 2C19 polymorphisms CYP2C19*2, *3, *4 and *5 associated with clopidogrel dosage variation, AKA “clopidogrel resistance.” The test may be used to screen patients prior to clopidogrel therapy in an effort to establish the correct dosage […]

Prasugrel Released July 10, 2009

Daiichi Sankyo and Eli Lilly & Co announced that their new thienopyridine Prasugrel (Effient®) was FDA-cleared July 10, 2009. Based on data generated in the TRITON-TIMI study of 13,608 patients, a loading dose of 60 mg followed by 10 mg/day reduces the combined rate of death from CV causes compared to clopidogrel 12.1% versus 9.9%. […]

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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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