Diagnostic Accuracy of Cerebrospinal Fluid Biomarkers Measured by Chemiluminescent Enzyme Immunoassay for Alzheimer Disease Diagnosis

In the last decades, an important role of cerebrospinal fluid (CSF) biomarkers for Alzheimer disease (AD) diagnosis has emerged. The evaluation of the triad consisting of 42 aminoacid-long amyloid-beta peptide (Aβ42), total Tau (tTau) and Tau phosphorylated at threonine 181 (pTau) have been recently integrated into the research diagnostic criteria of AD. For a long time, the enzyme-linked immunosorbent assay (ELISA) has represented the most commonly used method for the measurement of CSF biomarkers levels. This study aimed to assess the diagnostic accuracy of CSF biomarkers, namely Aβ42, tTau and pTau and their ratio, measured by fully automated CLEIA assay (Lumipulse). We included 96 patients clinically diagnosed as AD (48) and non-AD (48). All CSF biomarkers levels were measured on Lumipulse G1200 fully automated platform (Fujirebio Inc. Europe, Gent, Belgium). Aβ42 levels, 42/40 ratio, 42/tTau ratio, 42/PTau ratio were significantly reduced, and tTau and PTau levels were significantly increased in AD patients in comparison with non-AD patients. The receiving operator curve (ROC) analysis showed good diagnostic accuracy of all CSF biomarkers and their ratios for discriminating AD patients from non-AD patients, with 42/40 ratio having the best AUC (0.724, 95%CI 0.619-0.828;  < 0.001). Our findings support the use of CSF biomarkers measured by CLEIA method on a fully automated platform for AD diagnosis.