Charlie Muller, Helen Hayes Hospital TW, posted a question on the Medlab list, paraphrased here with his permission. He is validating the Akers PIFA Heparin/PF4 rapid assay kit for heparin induced thrombocytopenia with thrombosis, and needs a good way to validate it in addition to using Akers’ panels. Charlie’s setting is an acute rehab specialty hospital where a very large majority of patients have been exposed to heparin in various surgical procedures. They consult with a pathologist from Columbia University Medical Center who has had several discussions with the medical staff about HIT being a clinical diagnosis, using Warkentin’s 4T, etc. The staff want a little extra guidance from a rapid lab test.
From Prof. Jeanne Isabel, Northern Illihois University, a long-time friend and colleague. Hi George, a colleague who works at a cancer center has a patient on hydrocortisone (not sure how much) and her prothrombin time and international normalized ratio (PT/INR) were elevated to 54 s/4.9. she is on Coumadin and last time her INR was in the therapeutic range. She did not have symptoms to correlate with the elevated results. would the hydrocortisone cause this? Thanks.
A second great question from our Rutgers graduate hemostasis course participants, this one from Brandy Gunsolus, Healthplex Family Clinic in Shreveport, LA, and Jene Shafer from Orange Regional Hospital, Middletown, NY. We are studying the new cell-based model of coagulation and they ask whether the storage lesion of platelet concentrates affects their ability to be activated in vivo upon administration. The cell-based model relies on collagen and thrombin-activated (COAT) platelets; they wonder if stored platelets are able to be activated as effectively as patient’s own platelets. I have found no studies examining this question.
From Gnaesh Lyer, Florida Hospital: Have you done any correlation studies for Plavix and aspirin if the tubes are sent by tube system from floors rather than hand delivering the tubes? Does the results vary a lot or with in acceptable range? Thanks.
Hello, Gnaesh Lyer, and thank you for your question. I know of no studies that examine the effect of specimen tube system agitation affecting platelet function assay results, and have forwarded your question to several colleagues to learn if anyone has unpublished data on the subject. Perhaps one of our participants may have a comment to add.
From Yvonne Ellis, Hematology Technical Supervisor, IU Health Bedford Laboratory: George, I counseled a physician today about ordering protein C and S on a patient who has a confirmed pulmonary embolism. I told him during a clot was not the time to test for these. He did seem to have a good understanding of the workings of the regulators. He seemed to think though that if someone normally had low levels of these, that the levels would be markedly decreased during a clot process. I told him there is no established evidence of how much prot C and prot S are decreased in a clot formation. It would be different per person and per clot. Was I correct in this? Have there been studies about this subject?
I enjoy the e-mails I receive from the Fritsma Factor. I teach hematology/coag at a 2 year MLT program and use the text you collaborated on with Prof. Rodak. It is a great text. Thank you for any help.
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From Karen Dallas, MD, Saskatoon Health Region: I have searched the internet and cannot find a direct connection between thromboembolism prophylaxis with direct thrombin inhibitors and the induction of a prothrombotic state once discontinued. We have observed a few cases which seem to exhibit this phenomenon at my institution. Can you guide me towards any information on this occurrence?
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From Ali Sadeghi-Khomami: Hi George, I read Dave McGlasson’s paper with great interest. In brief, his case had the following results:
|PTT 2 h 37°C incubation||>200s|
|Platelet neutralization (PNP)||Positive|
|Kaolin clotting time (KCT)||>200s|
- The article didn’t mention anything about a prolonged PT mix but just PTT have done that way.
- The PNP positive, could be a false positive due to factor V release from platelets.
- Later follow up: DRVVT screen and confirm both positive
- Staclot-LA negative, no data provided other than result on your site.