Evaluation of plasma neurofilament and glial fibrillary acidic protein to predict or detect amyloid related imaging abnormalities

Abstract INTRODUCTION Amyloid‐targeting therapies (ATT) require frequent magnetic resonance imaging monitoring to detect vasogenic edema and hemorrhage, i.e., amyloid‐related imaging abnormalities (ARIA). Neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) are potential blood‐based biomarkers (BBM) of ARIA. METHODS Plasma NfL and GFAP were longitudinally collected in an ATT clinic and natural log transformed. Baseline, pre‐ARIA, and trajectories were compared between patients with ( N =  15) and without ( N =  45) ARIA. RESULTS Baseline NfL and GFAP did not differ between patients with or without ARIA (ln[NfL] ECLIA 1.24 ± 0.38 pg/mL vs 1.25 ± 0.40 pg/mL, p =  0.77; ln[NfL] Simoa 2.87 ± 0.47 pg/mL vs 2.98 ± 0.40 pg/mL, p =  0.30, ln[GFAP] ECLIA 4.95 ± 0.36 pg/mL vs 4.88 ± 0.47 pg/mL, p =  0.69). No significant changes were seen at the timepoint preceding ARIA, and ARIA incidence made no detectable impact on biomarker trajectories. DISCUSSION Biobanking in treatment clinics can evaluate clinical utility of BBMs as monitoring tools. These findings do not support a strong association between NfL or GFAP and ARIA in the ATT clinic.