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Anticoagulation in Renal Dialysis

A hypothetical case study: a patient whose birthdate was 9-20-1945 had ESRD and non-valvular atrial fibrillation. He had been on renal dialysis since 2011 and had been taking Coumadin since 2005, maintaining an INR of 2.7, even after dialysis was initiated. In the summer of 2014 he experienced a soft-tissue bleed, prompting his nephrologist to […]

Anticoagulant Therapy

Mixing Study Incubation Time

From Heather DeVries. Hi George! Do you know the reasoning behind using a 2-hour vs 1-hour incubation in mixing studies? We have always used 2 hours, and I wonder if it has to do with the heterogeneity of the antibodies we are trying to pick up. Our pathologist probably has a very good explanation, but […]

PPP Validation

From Heather DeVries: Greetings! We were inspected by CAP this week, and at one facility they questioned the validation of PPP. Our current procedure, written in 2001, states that the AVERAGE of 10 specimens must yield a platelet count of less than 5000/uL in order to validate a centrifuge. At the facility in question, one […]

Specimen Management

Hemophilia: Bispecific Antibody

Here is an editorial that appeared in the December, 2016 Journal of Thrombosis and Haemostasis describing the thinking that led to a coagulation factor VIII mimetic. This is a bispecific antibody that approximates factors IX and X to activate X while bypassing factor VIII. Designated ACE910, the mimetic enables normal clotting in hemophilia A when […]

Bleeding Disorders

Chromogenic VIII and IX Assays

What are the most accurate and reproducible assays for factors VIII and IX. For answers, I recommend an excellent educational article, Adcock D, Pruthi R, Tiefenbacher S, The value of the chromogenic activity assay in diagnosis and therapeutic monitoring of hemophilia. Med Lab Observer 2017, February, 8–14.

Bleeding Disorders

Unable to Obtain Dimer Result on Xarelto

From Heather DeVries, Indiana University Health. Hi George! We use the DDHS kit from IL on our TOP series instruments. There is a cancer patient at one of our facilities who has not been able to get a dimer result while on Xarelto. From the error codes, it looks like it would be human anti-mouse […]

Anticoagulant Therapy

Acquired Glanzmann

Dr. Sarode’s February 17 post mentioned acquired Glanzmann thrombasthenia (GT). I’ve attached a case study describing and defining this autoimmune bleeding disorder. By coincidence, Heather DeVries saw an acquired GT in the Indiana University Medical Center lab. Heather used her own platelets as a control to demonstrate how the patient’s antibody suppressed normal platelet aggregation. […]

Bleeding Disorders

Yet More: Whole Blood Aggregometry

From Ravinda (Ravi) Sarode, MD, Chief of Pathology, University of Texas Southwestern Medical Center, Dallas. Hey George, sorry for late response. I have used WBA since 1987! I have made comparisons between the two methods and every time found WBA more sensitive. One example I will quote is a patient with CLL who had easy […]

Platelet Function Testing

More on Whole Blood Aggs

Here’s additional follow-up to Heather DeVries’s February 9 whole blood lumiaggregometry discussion, which attracted comments from Bob Gosselin, Dave McGlasson, and Drs. Catherine Hayward and Emmanuel Favaloro. Dr. Favaloro references the effort to clean cuvettes and probes in the whole blood system, so I want to reassure Heather that these components are now disposable. I’m […]

Platelet Function Testing

More on Polycythemia and Anticoagulant Volume

More on anticoagulant adjustment from Heather DeVries: There is more to our story on adjusting sodium citrate for high hematocrits. We have a pediatric patient who is getting multiple draws, for multiple assays, throughout the day. Sometimes there is PT and/or PTT, but sometimes not. The techs are confused as to when the draw must […]

Specimen Management

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George Fritsma is a medical laboratory scientist, educator, and author. George is a member of the International Society on Thrombosis and Hemostasis, the International Society for Laboratory Hematology, and the American Society for Clinical Laboratory Science.

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