Platelet and Erythrocytes

Platelet interaction with erythrocytes and propensity to aggregation in essential thrombocythaemia

Mia-Jeanne van Rooy, PhD

,

 Prof Etheresia Pretorius, PhD

Published Online: 14 May 2015

DOI: http://dx.doi.org/10.1016/S0140-6736(14)62293-5

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Article Info

• Summary
• Full Text
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3 years after diagnosis with essential thrombocythaemia (JAK2 Val617Phe mutation) in January, 2011, a healthy 26-year-old white woman was referred to the Applied Morphology Research Centre at the University of Pretoria for an ultrastructural blood analysis because of a platelet count of 1240 × 109 cells per L (normal range 150–300 × 109 cells per L). Essential thrombocythaemia is a myeloproliferative disorder characterised by hyperplasia of megakaryocytes in the bone marrow and thrombocytosis. The JAK2 Val617Phe mutation is present in about 50% of people with essential thrombocythaemia and leads to megakaryocyte hyperplasia and consequent thrombocytosis. Although other organs such as the liver can be affected, our patient had no organ involvement, and no history of thrombosis. She was not on any regular medication, had no other medical history, and did not smoke.

Pradaxa

Minor Trauma Led to Death in Pradaxa Patient

By Crystal Phend, Senior Staff Writer, MedPage Today

Published: March 06, 2012

Reviewed by Zalman S. Agus, MD; Emeritus Professor, Perelman School of Medicine at the University of Pennsylvania.

Action Points

• Dabigatran etexilate is an oral anticoagulant that acts as a direct, competitive thrombin inhibitor. It does not require routine monitoring and has been approved by the FDA for the prevention of stroke and systemic embolism in patients with atrial fibrillation.
• Note, however, that no effective reversal agent for dabigatran in the event of catastrophic hemorrhage has been identified.
• This case report indicates an example of catastrophic hemorrhage after mild traumatic brain injury, and the authors suggest measuring thrombin time and instituting the early use of dialysis in conjunction with intravenous fluid administration to maintain renal perfusion.

A dabigatran (Pradaxa) patient's death from a brain hemorrhage following a fall has again highlighted concerns over lack of an effective reversal agent for the drug.

Despite treatment with recombinant factor VII, the 83-year-old man deteriorated rapidly as the bleeding spread across most of the left hemisphere of his brain in just six hours, according to Richard H. Schmidt, MD, PhD, of the University of Utah in Salt Lake City, and colleagues./.../

Flu Shot Reduces Venous Clot Risk

AHA: Flu Shot Reduces Venous Clot Risk

By Crystal Phend, Staff Writer, MedPage Today Published: November 09, 2008 Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco

NEW ORLEANS, Nov. 9 -- Vaccination against the flu may also protect against venous thromboembolism, researchers found. In a case-control study, adults who got their immunizations were 26% less likely to develop venous thromboembolism over the next year, Joseph Emmerich, M.D., Ph.D., of the University Paris Descartes, and colleagues reported at the American Heart Association meeting here. The effect was greatest -- a 48% reduction -- before age 52, they added. The influenza virus increases blood viscosity, while the systemic inflammation caused by such infections can also trigger a thrombotic response, the researchers noted. Dr. Emmerich's group speculated that this might have been the mechanism for the protective effect of influenza vaccination, but they noted that clotting events did not vary by season of the year for vaccinated or unvaccinated patients./.../

AHA: Flu Shot Reduces Venous Clot Risk

By Crystal Phend, Staff Writer, MedPage Today
Published: November 09, 2008
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco

NEW ORLEANS, Nov. 9 -- Vaccination against the flu may also protect against venous thromboembolism, researchers found.

In a case-control study, adults who got their immunizations were 26% less likely to develop venous thromboembolism over the next year, Joseph Emmerich, M.D., Ph.D., of the University Paris Descartes, and colleagues reported at the American Heart Association meeting here.

The effect was greatest -- a 48% reduction -- before age 52, they added.

The influenza virus increases blood viscosity, while the systemic inflammation caused by such infections can also trigger a thrombotic response, the researchers noted.

Dr. Emmerich's group speculated that this might have been the mechanism for the protective effect of influenza vaccination, but they noted that clotting events did not vary by season of the year for vaccinated or unvaccinated patients./.../