Figure 2.

CSF IGFBP2 is associated with CSF and PET Alzheimer’s disease biomarkers in the asymptomatic PREVENT-AD cohort. CSF IGFBP2 levels were measured using the Olink Proximity Extension Assay (n = 109). CSF Alzheimer’s disease (AD) biomarkers (A) amyloid-beta 42 (Aβ₄₂) (B) phosphorylated tau 181 (p₁₈₁-tau) and (C) total tau (t-tau) were measured using validated Innotest ELISA kits, following the standardized protocols established by the BIOMARKAPD consortium (n = 101). (D) The global cortical amyloid standardized uptake value ratio (SUVR) was measured using ¹⁸F-NAV4694 (n = 46). (E) Tau deposition in the entorhinal cortex was measured with flortaucipir (n = 49). The synaptic markers (F) SNAP25 (n = 106), (G) SYT1 (n = 106), (H) GAP43 (n = 46) and (I) NRGN (n = 46) were quantified using immunoprecipitation followed by mass spectrometry. Significant or trend-level linear regressions are represented with a confidence region of the fitted line. R² , β- and P-values are located in the top left corners of each panel. Analyses were adjusted for age, sex and APOE ɛ4 carrier status. a.u. = arbitrary units; BIOMARKAPD = Biomarkers for Alzheimer's and Parkinson's disease; IGFBP2 = insulin-like growth factor binding protein-2; NPX = Normalized Protein eXpression; PREVENT-AD = PRe-symptomatic EValuation of Experimental or Novel Treatments for Alzheimer's Disease.