Israel Medical Association Journal

Background: Neurofilament light chain (NfL) is an established biomarker for detecting axonal injury in various neurological disorders. The Quanterix Single Molecule Array (Simoa) is the current standard; however, automated immunoassays, such as the Siemens Atellica and Centaur, may serve as alternatives.

Objectives: To compare NfL measurements obtained with the Centaur system to those from the Simoa-SR-X. To assess their agreement and applicability in clinical practice, research, and animal studies.

Methods: NfL levels were measured in 27 human serum, 8 plasma, and 16 cerebrospinal fluid (CSF) samples, and 9 murine serum samples, by Centaur and Simoa systems. NfL levels in concomitantly drawn serum and plasma were compared in 8 humans. The agreement between platforms was evaluated.

Results: NfL levels measured by Centaur and Simoa systems demonstrated a strong correlation in serum (Spearman r=0.97, P < 0.0001) and plasma (Pearson R²=0.95, P < 0.0001). Centaur measurements were higher (P = 0.01) than Simoa. Most importantly, system-specific Z-scores corrected these differences. Serum and plasma levels measured by the Centaur system correlated strongly (R²=0.98, P < 0.0001) and showed similar results. CSF levels measured by the Centaur system were lower (52% bias) than those measured by Simoa, with poor correlation at concentrations within the normal range (R²=0.32, P = 0.11). Mouse serum results showed a strong correlation between systems (R²=0.86, P < 0.001) with similar values.

Conclusions: The Centaur system offers an alternative to Simoa for measuring NfL in human serum, plasma, and murine serum. System-specific age-adjusted Z-scores are essential for interpretation. CSF evaluation requires further assessment.

Endovascularly retrieved clots may be a potential resource for diagnosing stroke etiology. This method may influence secondary prevention treatment. We measure thrombin activity eluted by serially washing clots. We concluded that an assay measuring the change in thrombin in clots retrieved during acute stroke endovascular thrombectomy procedures may serve as a diagnostic marker of the origin of the clot. The suggested mechanism for these differences may be the clot location before its retrieval, with high blood flow causing thrombin washout in atherosclerotic clots, in contrast to atrium appendage low blood flow retaining high thrombin levels.