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A multi‐center evaluation of TECHNOSCREEN ® ADAMTS‐13 activity assay as a screening tool for detecting deficiency of ADAMTS‐13
Author(s) -
Moore Gary W.,
Meijer Daniëlle,
Griffiths Margaret,
Rushen Lucy,
Brown Alice,
Budde Ulrich,
Dittmer Rita,
Schocke Barbara,
Leyte Anja,
Geiter Sabine,
Moes Anneke,
Cutler Jacqueline A.,
Binder Nikolaus B.
Publication year - 2020
Publication title -
journal of thrombosis and haemostasis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 178
eISSN - 1538-7836
pISSN - 1538-7933
DOI - 10.1111/jth.14815
Subject(s) - adamts , thrombotic thrombocytopenic purpura , medicine , thrombotic microangiopathy , thrombospondin , metalloproteinase , platelet , matrix metalloproteinase , disease
Background Quantifying A disintegrin‐like and metalloprotease with thrombospondin type 1 motif, member 13 (ADAMTS‐13) activity enhances thrombotic thrombocytopenic purpura (TTP) diagnosis but most assays are time consuming, technically demanding, and mainly available in reference centers. Objective Evaluate a simple, semiquantitative ADAMTS‐13 activity screening test for early identification/exclusion of TTP. Patients/Methods Plasma from 220 patients with suspected thrombotic microangiopathy at three reference centers were tested with TECHNOSCREEN ® ADAMTS13 activity screening test in comparison with TECHNOZYM ® ADAMTS‐13 activity ELISA at two centers, and in‐house fluorescence resonance energy transfer assay at the third center. The screening test indicates if ADAMTS‐13 activity is at one of four level‐indicator points: 0, 0.1, 0.4, or 0.8 IU/mL. Results Screen results were interpreted as binary data in that ADAMTS‐13 activity was above or below the 0.1 IU/mL TTP clinical threshold. Combining all sites' data, the screen exhibited 88.7% sensitivity, 90.4% specificity, 74.6% positive predictive value, and 96.2% negative predictive value, comparable to published data for quantitative assays. Five samples with quantitative results below the threshold gave screen readings of 0.1 IU/mL and seven marginally above the threshold gave screen readings of zero. All would warrant plasma exchange while the level is quantified. Nine samples with normal/near normal results gave screens of zero and confirmatory quantifications would prompt early treatment withdrawal, as is current practice. One sample generated screen/quantitative results of 0.4/0.00 IU/mL respectively and was the only clear false‐negative. Conclusions The screening test provides more rapid ADAMTS‐13 level evaluation than most currently available assays. Its simple operation renders it suitable for adoption in routine or specialist laboratory environments.