Evaluation of the EUROIMMUN automated chemiluminescence immunoassays for measurement of four core biomarkers for Alzheimer's disease in cerebrospinal fluid

Katharina Römpler; Philipp Arendt; Britta Brix; Viola Borchardt-Lohölter; Anette Schulz; Mandy Busse; Stefan Busse

doi:10.1016/j.plabm.2024.e00425

Evaluation of the EUROIMMUN automated chemiluminescence immunoassays for measurement of four core biomarkers for Alzheimer's disease in cerebrospinal fluid

Pract Lab Med. 2024 Sep 5:41:e00425. doi: 10.1016/j.plabm.2024.e00425. eCollection 2024 Aug.

Authors

Katharina Römpler¹, Philipp Arendt¹, Britta Brix¹, Viola Borchardt-Lohölter¹, Anette Schulz¹, Mandy Busse^{2

3}, Stefan Busse³

Affiliations

¹ Institute for Experimental Immunology, Affiliated to EUROIMMUN Medizinische Labordiagnostika AG, Seekamp 31, 23560, Luebeck, Germany.
² Department for Experimental Obstetrics and Gynecology, Otto von Guericke University Magdeburg, Medical Faculty, Gerhart-Hauptmann-Str. 35, 39180, Magdeburg, Germany.
³ University Hospital for Psychiatry and Psychotherapy, Otto von Guericke University Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany.

Abstract

Introduction: Robust immunoassays for quantification of Alzheimer's disease (AD)-specific biomarkers are required for routine diagnostics. We report analytical performance characteristics of four new chemiluminescence immunoassays (ChLIA, EUROIMMUN) running on closed, fully automated random-access instruments for quantification of Aβ_1-40, Aβ_1-42, tTau, and pTau(181) in human cerebrospinal fluid (CSF).

Methods: ChLIAs were validated according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI). Optimal cut-offs for biomarkers and biomarker ratios were determined using samples from 219 AD patients and 220 patients with AD-related symptoms. For performance comparison, biomarker concentrations were measured in 110 diagnostic leftover samples using the ChLIAs and established Lumipulse G assays (Fujirebio).

Results: All ChLIAs met CLSI criteria. Overall agreement between assays was 89.0%-97.3 % with highly correlating results (Pearson's correlation coefficients: 0.82-0.99). Passing-Bablok regression analysis revealed systematic differences.

Discussion: EUROIMMUN ChLIAs showed good analytical performances and represent new valuable tools for diagnostics of AD.

Keywords: Alzheimer's disease; Biomarkers; Cerebrospinal fluid; Chemiluminescence; Immunoassay; Validation.