Performance Evaluation of an Automated Neurofilament Light Chain Immunoassay

Increased neurofilament light chain (NfL) in cerebrospinal fluid and blood indicates recent neuroinflammatory damage and is prognostic of disease worsening (JAMA Neurol 2023;80:1317-25). These studies evaluate the analytical performance of the Siemens Healthineers Atellica IM NfL assay, testing serum and plasma, on the Atellica IM analyzer.

Detection capability, linearity, dilution recovery, precision, interfering substance testing, specimen equivalence, method comparison studies, and determination of expected values are all described and performed according to CLSI standards.

The limit of blank, detection, and quantitation were 1.5, 2.0, and 3.0 pg/mL, respectively. The analytical measuring interval was 3.0 to 300.0 pg/mL with on-board dilutions extending the reportable range to 3000 pg/mL. Repeatability and within-lab precision ranged from 0.9% to 5.7% CV and 1.5% to 8.6% CV, respectively. No significant interference was detected for biotin or 38 other substances. Serum SST and plasma EDTA samples provided equivalent NfL results. Comparison of the NfL assay across Siemens Healthineers platforms (Atellica IM, ADVIA Centaur XP/XPT systems) showed strong alignment; the Atellica IM NfL assay also strongly aligns to the early phase certified reference material (Clin Chem Lab Med 2023;61:1245-54). Age-specific expected values for healthy adults were provided, with an overall central 95th percentile range of 3.7 to 18.9 pg/mL.

The Siemens Healthineers Atellica IM NfL assay demonstrated strong performance in all categories of assay development and verification; importantly, results from both healthy and multiple sclerosis patients fall within the reportable range. The Atellica IM NfL assay is for in vitro diagnostic use in the quantitative measurement of NfL in human serum and plasma (EDTA) using the Atellica IM analyzer.