Cerebrospinal fluid levels of amyloid-beta oligomers, Aβ42, t-tau and p-tau in Cohort 2. Alzheimer’s disease subjects (AD, n = 10), mild cognitive impairment subjects (MCI, n = 10) and age-matched controls (CON, n = 10) were analyzed for amyloid-beta oligomers (oAβ) (A), Aβ42 (B), total tau (t-tau) (C) and phosphorylated tau (p-tau) (D). Aβ42, t-tau and p-tau were measured with the Luminex platform (Luminex Corporation, Austin, TX, USA) and the AlzBio3 kit (Fujirebio Europe, Ghent, Belgium). This kit simultaneously measures Aβ1–42, t-tau and P-tau181 in 75 μl cerebrospinal fluid. Horizontal bars, medians and interquartile ranges. Dashed line crosses y axis at 0.15 pg/ml, indicating the lower limit of reliable quantification. Erenna platform (Singulex, Alameda, CA, USA).