Real-world evaluation of a novel automated method for measuring ADAMTS-13 activity using the Ceveron s100 analyzer.

Background: Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy characterized by a severe functional deficiency of ADAMTS-13. Measuring ADAMTS-13 activity is crucial for diagnosing TTP (<10 IU/dL), monitoring treatments, and detecting relapses (<20 IU/dL). The Technofluor assay (Technoclone) allows a rapid ADAMTS-13 activity measurement using the Ceveron s100 analyzer (Technoclone).

Objectives: This study aimed to evaluate the analytical and clinical performance of this new test under real-world conditions.

Methods: ADAMTS-13 activity was measured using 2 fluorometric methods: the Technofluor ADAMTS-13 activity on the Ceveron s100 (Technoclone) and our reference fluorescence resonance energy transfer-VWF73 method, in plasma samples collected under real-life conditions (January 12, 2024, to April 4, 2024) and retrospectively selected samples from our biobank. The analytical and clinical performance of the new test was assessed, focusing on the critical low levels (<30 IU/dL).

Results: Four hundred samples were tested under real-world conditions and 100 others tested retrospectively. The Technofluor assay showed excellent analytical performance, with a detection limit of 0.1 IU/dL, repeatability coefficient of variation of <11%, and reproducibility coefficient of variation of 6.1% (high level, 90 IU/dL) and 7.5% (low level, 40 IU/dL). Clinical performances were strong at diagnosis (threshold, 10 IU/dL; sensitivity and positive predictive value, 1.0) and during the follow-up (threshold, 20 IU/dL; specificity, 1.0; 95% CI, 0.99-1.00; positive predictive value, 0.96; 95% CI, 0.90-1.01; negative predictive value, 0.98; 95% CI, 0.97-1.00). No analytical interference was observed.

Conclusion: The Technofluor assay on the Ceveron s100 is a fast, reliable method for measuring ADAMTS-13 activity, proving effectiveness for diagnosis and monitoring of TTP patients. However, it remains crucial to interpret ADAMTS-13 activity measurement with clinical context to ensure accurate diagnosis and management.