As described previously, CSF was collected according to routine clinical procedures following the Alzheimer’s Association Flow Chart for lumbar puncture, centrifuged, frozen at −80C on dry ice, and shipped for analysis16 (link). Plasma was collected in EDTA-plasma tubes and centrifuged (2,000g, +4 C) for 10 minutes. Following centrifugation, plasma from all tubes were transferred into one 50 ml polypropylene tube and mixed, after which 1ml was aliquoted into 1.5ml polypropylene tubes and stored at −80C within 30 – 60 minutes of collection. All plasma samples underwent one freeze-thaw cycle when 200μl were further aliquoted into 0.5ml LoBind tubes and the 200μl aliquots were stored at −80C as described previously14 (link). Prototype immunoassays on a cobas e 601 and e 411 analyzer (Roche Diagnostics International Ltd, Rotkreuz, Switzerland) were used at the Clinical Neurochemistry laboratory in Gothenburg to analyze Aβ42, Aβ40, NfL and GFAP 17 (link)–19 (link). Plasma and CSF P-tau217 were measured using an assay developed by Eli Lilly and analyzed at Lund University as previously described14 (link).