Discrepancies between ADAMTS13 activity assays in patients with thrombotic microangiopathies

Ian Mackie, Katy Langley, Andrew Chitolie, Ri Liesner, Marie Scully, Samuel Machin, Flora Peyvandi

Research output: Contribution to journalArticlepeer-review


ADAMTS13 activity assays are sometimes useful in confirming the clinical diagnosis or to distinguish different thrombotic microangiopathies (TMA). We investigated the commonly used clinical assays for ADAMTS13 activity. 159 samples from normal subjects or acquired TMA patients were studied in collagen binding (CBA), Fret and chromogenic peptide substrate assays. Frozen aliquots of pooled normal plasma gave similar values by CBA, Fret-VWF73 peptide, Fret-VWF86 and chromogenic VWF73 ELISA (chr-VWF73). Two lyophilised commercial calibrants gave lower ADAMTS13 activity by CBA than peptide substrate assays. The addition of solid HEPES to normal plasma caused a significant fall in CBA, but not Fret-VWF73 activity and might partly explain the differences, since lyophilised plasmas are often HEPES buffered. Normal plasmas showed good agreement between CBA and Fret assays, although chr-VWF73 gave slightly higher values. In acquired TMA, there was reasonable agreement between assays for samples with

Original languageEnglish
Pages (from-to)488-496
Number of pages9
JournalThrombosis and Haemostasis
Issue number3
Publication statusPublished - Jan 10 2013


  • ADAMTS13
  • ADAMTS13 activity assay
  • TMA
  • TTP

ASJC Scopus subject areas

  • Hematology


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