Elagic Acid-based PTT Reagent

From Kelly Rose at Novartis: Hi George, I work in a research lab and we are interested in comparing different partial thromboplastin time (PTT) reagents on our Stago Sta-R. Currently we use the silica-based (STA PTT-Automate) and kaolin-based STA C. K. Prest. We would like to try ellagic acid. Have you had any experience with this reagent? and […]

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Screening Assays

Sep 13 2012

george

PTT Reagent LA Sensitivity in Mixing Studies

Hello George, My name is Marcelo Gonçalves, clinical pathologist from Hematology Department of Hermes Pardini Laboratory, Brazil. I would like to ask what kind of activated partial thromboplastin time (APTT, PTT) reagents should be used in APTT mixing studies (high or low responsiveness to LA)? Thank you for your attention. Dr. Marcelo Luide Pereira Gonçalves Thank […]

Lupus Anticoagulant

Validating High POC INR Results

Our April 24, 2012 post (and Quick Question), POC: When to Validate a High INR has attracted a provocative comment from Alan Neal of New Zealand. I’ve added this link so the comment does not get buried and to attract additional discussion from our participants.

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Anticoagulant Therapy

Sep 12 2012

george

Validating High POC INR Results

Our April 24, 2012 post (and Quick Question), POC: When to Validate a High INR has attracted a provocative comment from Alan Neal of New Zealand. I’ve added this link so the comment does not get buried and to attract additional discussion from our participants.

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Anticoagulant Therapy

Aug 25 2012

george

How Rapidly Does INR Decrease?

Here is a question that came to me from the American Society for Clinical Laboratory Science Consumer Web Forum: How quickly will an elevated international normalized ratio (INR, PT/INR) decrease/time? I appreciate the answer may be “it depends,” but for patients on warfarin and with an elevated INR (for example 4.0 in a patient with and INR […]

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Anticoagulant Therapy

Jul 29 2012

george

PT Reagents

From Donna Lawler, University of Wisconsin: George, I have been reading with interest the ongoing discussion of PTT reagent selection and enjoyed the corresponding article you cited. I was wondering if you have any similar literature references concerning protime/INR reagents. We use a thromboplastin that has a low ISI (close to 1.0) and good factor sensitivities […]

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Anticoagulant Therapy

Jul 14 2012

george

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

PTT Reagent Selection

For those who participated in our summer, 2011 questionnaire (designed by Precision BioLogic’s marketing analyst Mr. Ankush Randhawa) about the choice of PTT reagent relative to its application and sensitivity to lupus anticoagulant, the results now appear in Fritsma GA, Dembitzer FR, Randhawa A, Marques MB, Van Cott EM, Adcock-Funk D, Peerschke EI. Recommendations for appropriate […]

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Anticoagulant Therapy

Feb 17 2012

george

More on PTT Specimen Storage Time

On November 1 I replied to a question from Joe Lamb, Columbus, GA about room temperature storage of specimens for partial thromboplastin time (PTT) assays that are sent to reference laboratories. Joe was concerned that his reference lab claimed PTT results were valid on specimens less than 24 hours old, whereas the CLSI Guideline H21-A5 sets […]

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Anticoagulant Therapy

Feb 1 2012

george

PT and PTT for Preoperative Screens

I’m having some fun this week teaching a unit in the online graduate hemostasis course at the University of Medicine and Dentistry of New Jersey at the invitation of Drs Elaine Keohane and Nadine Fydryszewski. This also gives me the opportunity to work with colleagues Donna Castellone and Dr. Larry Smith. Many of our twelve students are seasoned veterans in hematology […]

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Screening Assays

Screening Assays

Elagic Acid-based PTT Reagent

PTT Reagent LA Sensitivity in Mixing Studies

Validating High POC INR Results

Validating High POC INR Results

How Rapidly Does INR Decrease?

PT Reagents

APCR Screening: Everyone?

PTT Reagent Selection

More on PTT Specimen Storage Time

PT and PTT for Preoperative Screens

George Fritsma MS MLS

Cheat Sheets from George

Questions or Comments?

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