ADAMTS13

Clinical Relevance

ADAMTS13 is a metalloprotease which limits platelet aggregation and microthrombi information in the microcirculation be cleaving the Von Willebrand Factor to generate a series of small molecular weight multimers.

A deficiency of ADAMTS13, either because of an inherited mutation within ADAMTS13 gene of the development of an autoantibody, leads to the potentially lethal syndrome of Thrombotic Thrombocytopenic Purpura (TTP).

ADAMTS13 analysis is performed by The National aHUS Service in Newcastle upon Tyne Hospitals to help differentiate between aHUS and TTP.

For aHUS advice please see Atypical Haemolytic Ureamic Syndrome (aHUS).

Minimum Volume

The volume of blood in coagulation samples must lie within the volume range as indicated by the size of the black fill arrow present on tubes. Volumes above or below the arrow will result in sample rejection to ensure validity of results.

Turnaround Time

24 hours

Age of Sample

Samples will be rejected if received more than 1 hours post venepuncture.

Specimen Requirements

2 blue top (sodium citrate) samples
All coagulation tubes must be adequately filled (see above)
All coagulation tubes must be mixed several times by gentle inversion immediately after venepuncture. Mixing the sample with the anticoagulant stops the sample clotting within the tube.
Requests must be performed following prior arrangement with a Haematology Consultant.

Limitations

It is not possible to provide results on clotted, insufficient, lipaeamic or haemolysed samples. These samples will be rejected with the appropriate comment.
Samples tubes that have expired cannot be accepted