Measuring ADAMTS-13 activity to diagnose thrombotic thrombocytopenic purpura: a novel, fast fiber-optic surface plasmon resonance immunoassay

Quintijn Bonnez; Charlotte Dekimpe; Edwige Tellier; Gilles Kaplanski; Peter Verhamme; Claudia Tersteeg; Simon F De Meyer; Jeroen Lammertyn; Bérangère Joly; Paul Coppo; Agnès Veyradier; Karen Vanhoorelbeke

doi:10.1016/j.rpth.2023.102171

Measuring ADAMTS-13 activity to diagnose thrombotic thrombocytopenic purpura: a novel, fast fiber-optic surface plasmon resonance immunoassay

Res Pract Thromb Haemost. 2023 Aug 19;7(6):102171. doi: 10.1016/j.rpth.2023.102171. eCollection 2023 Aug.

Authors

Affiliations

¹ Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium.
² Aix-Marseille University, Institut National de la Santé et de la Recherche Médicale, INRAE, C2VN, Marseille, France.
³ Service de Médecine Interne et Immunologie Clinique, CHU Conception, Aix-Marseille University, APHM, Marseille, France.
⁴ Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium.
⁵ Department of Biosystems, Biosensors Group, KU Leuven, Leuven, Belgium.
⁶ Service d'Hématologie Biologique Hôpital Lariboisière, AP-HP and EA3518, IRSL, Université Paris Cité, Paris France.
⁷ Department of Hematology, Reference Center for Thrombotic Microangiopathies (CNR-MAT), Saint-Antoine University Hospital, AP-HP, Paris, France.
⁸ Centre de Référence des Microangiopathies Thrombotiques (CNR-MAT) AP-HP Paris France.

Abstract

Background: Thrombotic thrombocytopenic purpura (TTP) is characterized by severe ADAMTS-13 activity deficiency (<10%). Diagnostic testing is challenging because of unavailability, high cost, and expert technician requirement of ADAMTS-13 enzyme assays. Cost-effective, automated fiber-optic surface plasmon resonance (FO-SPR) platforms show potential for developing diagnostic tests. Yet, FO-SPR has never been explored to measure enzymatic activities.

Objectives: To develop an easy-to-use ADAMTS-13 activity assay utilizing optical fibers to rapidly diagnose TTP.

Methods: The ADAMTS-13 activity assay was designed and optimized using FO-SPR technology based on a previously described enzyme-linked immunosorbent assay setup. A calibration curve was generated to quantify ADAMTS-13 activity in plasma of healthy donors and patients with acute immune-mediated TTP (iTTP), hemolytic uremic syndrome, or sepsis. ADAMTS-13 activity data from FO-SPR and fluorescence resonance energy transfer-based strategies (FRETS)-VWF73 reference assays were compared.

Results: After initial assay development, optimization improved read-out magnitude and signal-to-noise ratio and reduced variation. Further characterization demonstrated a detection limit (6.8%) and inter-assay variation (Coefficient of variation, 7.2%) that showed good analytical sensitivity and repeatability. From diverse plasma samples, only plasma from patients with acute iTTP showed ADAMTS-13 activities below 10%. Strong Pearson correlation (r = 0.854) between FO-SPR and reference FRETS-VWF73 assays were observed for all measured samples.

Conclusions: A fast ADAMTS-13 activity assay was designed onto automated FO-SPR technology. Optimization resulted in sensitive ADAMTS-13 activity measurements with a detection limit enabling clinical diagnosis of TTP within 3 hours. The FO-SPR assay proved strong correlation with the reference FRETS-VWF73 assay. For the first time, this assay demonstrated the capacity of FO-SPR technology to measure enzymatic activity in pre-clinical context.

Keywords: ADAMTS-13 protein; diagnostic testing; enzyme assays; optical fibers; purpura; thrombotic thrombocytopenic.