CSF Biomarker Analysis for Alzheimer's Diagnosis

Lumbar puncture with subsequent measurement of CSF core biomarkers (Aβ₄₂, T-tau, and P-tau) was performed for all patients. Core biomarkers were analyzed with Innotest Kit enzyme-linked immunosorbent assays (Innogenetics, Ghent, Belgium) at the Department for Interdisciplinary Laboratory Medicine and Medical Biochemistry at Akershus University Hospital, Norway, which participates in the Alzheimer’s Association QC program for CSF biomarkers (Mattsson et al., 2011 (link)). Laboratory recommended cut-off values for a normal test were applied (Kalheim et al., 2018 (link)): Aβ₄₂ above 700 pg/ml; P-tau below 80 pg/ml; and T-tau below 300 pg/ml for patients younger than 50 years, below 450 pg/ml for patients aged 50–69 years, and below 500 pg/ml for patients older than 70 years.