Moore GW, Meijer D, Griffiths M, Rushen L, Brown A, Budde U, Dittmer R, Schocke B, Leyte A, Geiter S, Moes A, Cutler JA, Binder NB. A multi-center evaluation of TECHNOSCREEN
® ADAMTS-13 activity assay as a screening tool for detecting deficiency of ADAMTS-13.
J Thromb Haemost 2020;
18:1686-1694. [PMID:
32239643 DOI:
10.1111/jth.14815]
[Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 02/26/2020] [Accepted: 03/23/2020] [Indexed: 12/20/2022]
Abstract
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.
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