Platelet Function Testing

Correction Factor for ACD Solution

On September 28, 2016, Julia Hill asked, “Is there a standard calculation for using ACD tubes?” Her comment was appended to a 2009 entry describing HELLP syndrome, so it may have been buried deep in our database. George assumes Julia’s question relates to platelet satellitosis, which results from the action of an immunoglobulin potentiated in […]

Platelet Function Testing

Platelet Clumps on Blood Film

Susan Lemire asks, “Hi, what are most people doing when platelet clumps are found on the blood smear, but the platelet count is within normal range?” Hi, Susan, my hunch is that since we don’t review blood films when the CBC is within acceptable parameters, we probably miss some platelet clumping. CBC profiling instruments do […]

Platelet Function Testing

Reversing Plavix with PLT Concentrate

Larry Brace, PhD, Edward Hospital, Naperville, IL. writes that a pathologist is building a protocol to employ platelet concentrate transfusions for reversal of platelet inhibition for patients who are on Plavix or aspirin and are having bleeding or need surgery. He is looking for an objective way to quickly evaluate the status of the platelet […]

Platelet Function Testing

EDTA Vs. Citrated PLT Count

From Susan Lemire, Elliot Hospital, New Hampshire Hi George, I am validating the new Sysmex XN analyzer and they do not support a citrated platelet count for clumped platelets. In order to continue our current process, I am in the midst of doing a correlation between EDTA platelet counts vs. citrated counts. I have found […]

Platelet Function Testing

ADAMTS13 Method

From Donna Lawler, University of Wisconsin, Hi George. We are investigating the possibility of bringing an assay for ADAMTS 13 activity in house. We are looking at the two methods available (ELISA and FRET) and I am wondering what your experience is with either of these assays. I would love to hear from anyone that […]

Bleeding Disorders

More on PFA-100 Specimens

In follow-up to our 11/11/15 Collecting PFA-100 Specimens post, I’ve received responses from Donna Castellone and Drs. Ali-Sadeghi-Khomami and Emmanual Favaloro: First from Ms. Castellone: Most important is that your reference range reflects how you draw the patients–21 gauge, butterfly, the patients should be the same. Constancy is most important! Next, this detailed information from […]

Platelet Function Testing

Collecting PFA-100 Specimens

Here is a stimulating question sent to Dennis Ernst, Center for Phlebotomy Education, from a participant in his Phlebotomy Supervisors’ Boot Camp: One of our physicians asks that we collect specimens for PFA-100 assays using an 18g needle. Our laboratory scientists support this requirement, indicating that lab protocol requires that we not use a needle […]

Platelet Function Testing

Platelet Function Testing

From Ahmed Siddig Akasha: Please inform me about simple procedure of platelet aggregation test, the principle, procedure, and results interpretation and the normal values. Thank you. Hello, and thank you for your question, which provides me the opportunity to highlight our audio PowerPoint educational modules. You will find the information you request in modules 29–34, […]

Platelet Function Testing

Does Acetaminophen Interfere with the VerifyNow Asprin Test?

From Thomas Gage, MD, Lahey Medical Center. Greetings, I have a patient with a VerifyNow Aspirin test showing some inhibition. The patient had exposure to clopidogrel and acetaminophen, but not aspirin. So now I’m trying to figure out if acetaminophen can interfere with this test, and I’m getting conflicting opinions. Because the VerifyNow Aspirin test […]

Antiplatelet Therapy

Platelet Function Controls

A colleague asked George, can you please suggest a commercial normal and abnormal control one can use to test an assay that claims to distinguish normal from abnormal platelet function. Alternatively, suggest also please for preparing controls for research testing purposes. Specifically, how can we go about preparing a normal activity platelet control and an […]

Platelet Function Testing

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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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