Specimen Management

Lipemia, Hemolysis, and D-dimer

From “Cristina:” What is the reason why lipemic and hemolyzed coagulation sample should be rejected? Is it only the D-dimer is susceptible? Thanks. Hello, and thank you for your question. Lipemia is likely to cloud the final reaction solution in a photo-optical method, interfering with the results. On all instruments, the quantitative D-dimer is a […]

Heme Binds Factor VIII

There is a thought-provoking article in the June, 2012 issue of Journal of Thrombosis and Haemostasis: Repesse Y, Dimitrov JD, Peyron I, et al. Heme binds to factor VIII and inhibits its interaction with activated factor IX. J Thromb Haemostas 2012;10:1062–71. The authors do not speculate on in vitro specimen hemolysis, however their findings could provide additional […]

Specimen Management

How to Remove IgG

This question was posted on Wednesday, May 23 on Pat Letendre’s Medlab list and is reposted here with Linda Stang’s permission: We have a patient with lymphoma and an IgG peak (we think). The antibodies are interfering (and I mean really interfering) in the coags: INR >5.0 but has had clinical challenges with no bleeding. Is there any way to remove […]

Anticoagulant Therapy

More on Hemolysis: Dr. Marques

Here is a photo sent by my friend and colleague Marisa Marques, MD, director of the University of Alabama at Birmingham Hospital special coagulationand transfusion medicine laboratories. Her message was in response to the April 27 post on Hemolysis and the Heparin Anti-Xa by “Danagah.” The photo was taken in 2005 by special coagulation technologist Patti Tichenor of two specimens […]

Specimen Management

Platelet Clumping in Sodium Citrate: Reprise

From Kathy Jacobs at Chronolog, Inc. Hi George, When a patient’s platelets clump in sodium citrate, is there another anticoagulant that can be used to allow LTA platelet aggregation testing? Thanx in advance, Kathy. Hi, Kathy, good to “hear” from you. You posted your question originally as a comment to a

Platelet Function Testing

Hemolysis and Heparin Anti-Xa

A message from “Danagah:” Hi, George, How would you handle a sample for a chromogenic heparin anti-Xa assay if a patient is experiencing in vivo hemolysis and you cannot obtain a sample that is not hemolyzed? Would it make a difference as to the degree of hemolysis as to even accepting the sample? We reject […]

Anticoagulant Therapy

PT Stability for Open Specimens

A new specimen question from Pam Owens, TriCore Laboratories: Hi George, this is a question with two parts. Given that a PT is stable for 24 hrs in the original tube with the top on (never removed)… 1. How long is the sample good once the top has come off? 2. If the plasma has been removed, […]

Specimen Management

Does Elevated HCT Affect PT/INR?

Hello Mr. Fritsma, I am a pharmacy student working in an internal medicine clinic where we manage patients on warfarin. We had a question come in about how an elevated hemoglobin and hematocrit, HGB/HCT can affect INR levels as the lab is stating that as long as this patient’s hemoglobin is elevated, her INR results […]

Specimen Management

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 […]

Anticoagulant Therapy

Normal Plasma Storage

Here is a seemingly simple request from Vicki Lanigan at Niagara Health, Ontario, Canada: “I am looking for a reference for storage of normal pooled plasma (NPP, pooled normal plasma, PNP).” Vicki, this one drove me back to the books and to the package inserts for distributors Precision BioLogic Inc and George King Bio-Medical, Inc to learn the shelf life for […]

Specimen Management

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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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