As a member of the American Society for Clinical Laboratory Science (ASCLS) I have the opportunity to answer lab-related patient questions posted on the ASCLS Consumer Forum. This is a valuable service, first created by Dr. Susan LeClair at the University of Massachusetts in Dartmouth, that attracts an average of 100 questions a day and employs a large team of volunteer clinical laboratory scientists.

I got in over my head on a recent question and would like to get some help from our blog participants. A patient with essential thrombocythemia has taken Anagrelide daily for several to suppress platelet production. This is successful, but Anagrelide has reduced his kidney function and his glomerular filtration rate (GFR) now hovers at 30 mL/min.

I'm back at my computer and will be sorting e-mail and answering questions over the next two days. I'd like to thank Drs. John Olson and Dorothy (Dot) Adcock for their guest blogs, keeping the site fresh while I was gone with some great insights. We'll be seeing blogs from Drs. Marisa Marques and Kandice Marchant in the next two weeks, and a new series of modules on anticoagulant monitoring. I'd particularly like to thank Mr. David McGlasson, award-winning coagulation researcher from Wilford Hall USAF Medical Center in San Antonio, Texas for keeping an eye on the blog while I was gone. Geo.

Presenter: Dorothy Adcock-Funk, MD
Panelists: Kandice Kottke-Marchant, MD, PhD; Marisa B. Marques, MD; John D. Olson, MD, PhD
Moderator: George A. Fritsma, MS MT (ASCP)

Precision BioLogic Laboratory Medicine Roundtable, June 20 and 21, 2008, Dartmouth, Nova Scotia

In addition to Wendy Porteous, Steve Duff and Michael Scott, I would like to acknowledge Dean Willett, Sandy Morrison, and all the Precision BioLogic Inc. folks who participated in our round-table discussion.

We have employed the time-honored partial thromboplastin time assay (PTT, activated partial thromboplastin time, APTT) to monitor unfractionated heparin (UFH) and the intravenous direct thrombin inhibitors (DTIs) Argatroban (Novostan®), Lepirudin (Refludan®) and Bivalirudin (Angiomax®). Though we have developed and published therapeutic target ranges, the PTT suffers from several interferences. It is prolonged by parallel warfarin therapy, lupus anticoagulant, and congenital or acquired factor deficiency. In these circumstances the PTT anticoagulant response is exaggerated and unreliable. Conversely, elevated factor VIII and fibrinogen shorten the PTT and underestimate anticoagulant effect, a circumstance called in vitro drug resistance. The PTT does not lend itself to inter-laboratory normalization, as a variety of reagent and instrument combinations generate diverse anticoagulant responses.

A reminder: George is on vacation through July 16 and will check your questions sporadically, resulting in some delays. We'll be back at full speed July 17, 2008. Thank you.

Presenter: John D. Olson, MD, PhD
Panelists: Dorothy Adcock Funk, MD, Kandice Kottke-Marchant, MD, PhD, Marisa B. Marques, MD
Moderator: George A. Fritsma

Precision BioLogic Laboratory Medicine Roundtable, June 20 and 21, 2008, Dartmouth, Nova Scotia

First, I’d like to thank Wendy Porteous, Steve Duff, Michael Scott, and all the Precision BioLogic Inc. participants who organized the June round-table discussion. We had the opportunity to share a number of productive ideas.

As past chair and a member of the College of American Pathologists (CAP) Coagulation Resource Committee my colleagues and I have had the opportunity to review and analyze assay quantitative D-Dimer proficiency data from CAP 2001 and 2004 surveys and presented that data at the ISTH in 2005. Publication is planned for this and other related D-Dimer data. However, what was learned is a bit alarming and is preliminarily presented here.

Here's an interesting question from Anita D'Antonio.

Several of our hospitals Hematologists/Oncologists have concerns with the sensitivity of the reagent we use for Prothrombin testing. The reagent is Diagnostica Stago STA-Neoplastine Cl Plus with a 1.32 ISI. They believe the reagent is too sensitive and is generating needless consults and follow-up testing on patients who do not have a bleeding disorder. I believe the more sensitive assay is best. How can I present this information to the medical staff?

Anita D'Antonio

Click "Full Story" below to read David McGlasson's response.

I will be on vacation until July 16, so I will not be making any blog posts. However I have requested David McGlasson MS, CLS/NCA, from LackLand AFB to respond to any technical questions that may be posed while I am away.

Also, I am very happy to tell you that during the next two weeks you might see some guest posts from our respected colleagues Drs Olson, Marques and Adcock Funk.

And of course I will post anything interesting that I come across during my travels. So keep checking back for great new content. Geo.