This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Laboratory features

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

The laboratory findings in thrombotic thrombocytopaenic purpura include:

  • microangiopathic haemolytic anaemia:
    • fragmented red blood cells - schistocytes, helmet cells, triangle forms - in peripheral blood smear
    • normocytic, normochromic
    • Hb usually < 10 gm/dl
    • marked reticulocytosis; occasionally, nucleated RBC's
    • haemolysis - increased serum indirect bilirubin, LDH, and serum haemoglobin; absent haptoglobin
    • negative Coomb's test
  • thrombocytopenia - platelets usually < 50 000 per cu. mm
  • WBC's - normal or increased; neutrophils often increased
  • ADAMTS13 activity
    • severe deficiency of plasma ADAMTS13 activity (<10 IU/dL) with or without detectable inhibitory autoantibodies against ADAMTS13 supports the diagnosis of TTP if a patient presents with thrombocytopenia and microangiopathic hemolytic anemia (i.e. schistocytes, elevated serum lactate dehydrogenase, decreased hemoglobin and haptoglobin) without other known etiologies that cause thrombotic microangiopathy (TMA
    • normal to moderately reduced plasma ADAMTS13 activity (>20 IU/dL) in a similar clinical context supports an alternative diagnosis such as atypical hemolytic uremic syndrome (aHUS) or other types of TMA
  • coagulation tests - PT, PTT, fibrinogen - normal cf. DIC
  • elevated fibrin
  • urinanalysis - frequently, RBC's and protein; increased creatinine; rarely, oliguria
  • bone marrow - normal or increased megakaryocytes
  • gingival or skin biopsy may show capillary and arteriolar hyaline microthrombi, endothelial proliferation and subendothelial hyalinosis

Reference:


Create an account to add page annotations

Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.

Connect

Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.