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

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.