👤 Beau M Ances

Blood-based biomarkers are increasingly used to characterize Alzheimer's disease (AD)-related pathology, yet substantial heterogeneity exists in how biomarker burden relates to cognitive performance. Grip strength, a marker of frailty and functional reserve, may modify this relationship. We conducted a cross-sectional analysis of 348 participants from the Aging Adult Brain Connectome (AABC) study. Global cognition was assessed using the Preclinical Alzheimer Cognitive Composite (PACC). Plasma biomarkers included phosphorylated tau-217 (pTau Show less

This study evaluates plasma-based proteomic profiles for predicting amyloid positivity in adults with Down syndrome (DS) and examines the impact of apolipoprotein E ε4 (APOE ε4) on test performance. Cross-sectional data from 290 adults with DS were analyzed using single molecule array (SIMOA) technology to measure plasma amyloid beta (Aβ)42, Aβ40, neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), tau phosphorylated at threonine 181, and total tau. Amyloid burden was quantified using Pittsburgh Compound B and (18)F-florbetapir Aβ positron emission tomography. Support vector machine analyses were conducted with biomarkers as predictors and age, sex, and APOE ε4 carrier status as covariates. Age, GFAP, and NfL contributed the most to the model performance. The proteomic profile achieved an area under the curve (AUC) of 96% in models with and without APOE ε4. These findings suggest that plasma proteomic biomarkers can effectively identify amyloid positivity in adults with DS and may support clinical triage, monitoring, and selection for clinical trials, independent of APOE ε4 status. Show less