October 2021

Special edition for World Thrombosis Day (WTD).

What's it all about?

WTD marks the birthdate of Professor Rudolph Virchow, founder of pathology and the "triad". Well not actually. It turns out that he contributed only 2 of the 3 key factors considered important for thrombosis to occur. (Rudi can be found in Wikipedia between Rudolph the red nosed reindeer and Rudolph Nureyev). These 2 factors were hypercoagulability and stasis. Endothelial injury was added much later to form the triad now attributed to him.

Of course, we all know about tests on plasma for hypercoagulability and thrombotic risk such as ATIII, protein C and factor V (Leiden), etc. Also about travel thrombosis and the need to get the blood flowing (non static), but much less can be done to test for abnormal or activated endothelium.

Endothelium is important for stabilizing blood. There is enough TPA in normal endothelium to completely lyse all the fibrinogen in circulation, as shown by uncoagulable blood in victims of electrocution or envenomation by snakes such as Malayan pit viper. It is also the source of von Willebrand factor (vWF) which is important in both bleeding and thrombosis.

vWF propeptide assay

VWF propeptide has been proposed as a marker of abnormal endothelial function. (Nossent AY, et al. von Willebrand factor and its propeptide: the influence of secretion and clearance on protein levels and the risk of thrombosis. J Throm Haemostas. 2006; 4: 2556-2562). Its half-life in circulation is usually shorter than that of normal VWF. Any increase in ratio of vWF:PP to vWF:Ag suggests thrombosis or endothelial activation. Now new evidence showing its value in a prothrombotic condition has been published.

(Von Willebrand factor propeptide in severe coronavirus disease 2019 (COVID-19): evidence of acute and sustained endothelial cell activation" 2020 British Society for Haematology and John Wiley & Sons Ltd 719 British Journal of Haematology, 2021, 192, 714–719 Soracha E.Ward et al.).

It seems likely that endothelial dysfunction may persist in patients affected by "Long" Covid. There is a new ELISA by Senova Co, Germany for vWF:PP which we are pleased to offer for evaluations at reduced cost. It might provide more informative results if used in conjunction with vWF:CBA or ADAMTS13 testing. Who knows?

NSW freedom week update

Well, it looks like part of the Gladys legacy will be her ability to have coaxed (with a "freedom" carrot) the NSW population to take up the elusive vaccines. Not just once, but twice! Good to see that blood clots and other complications haven't been mentioned too much lately.

On this note, we thought we'd check up on the latest from the TGA on vaccine induced prothrombotic immune thrombocytopenia (VIPIT), or as the TGA like to say, thrombosis with thrombocytopenia syndrome (TTS).

To the 3rd October, there were 151 reported cases of TTS after vaccination with Vaxzevria (AZ) with 8 deaths. There were also 81 reports of Immune thrombocytopenia (ITP) post vaccination with 1 death. Myocarditis was reported 850 times post mRNA vaccination.

COVID-19 vaccine weekly safety report - 07-10-2021 | Therapeutic Goods Administration (TGA)

HEMOCLOT Protein C

As with the HEMOCLOT Protein S, Hyphen have released a larger presentation of HEMOCLOT Protein C. This product now comes in 3 x 2ml vials Ref #CK032K. The smaller presentation of 3 x 1ml is Ref #031K. Contact us for pricing.

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Haematex is the only Australian distributor which carries out local R&D into coagulation diagnostics.

When you purchase diagnostics from us, part of the money goes towards projects such as our own locally made DOAC-Stop, Inhibitor Dots, research on dRVVT and lupus anticoagulants.

Thanks for reading, we are grateful that we can act as your local coag news resource.

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