Plasma ptau231 predicts locus coeruleus integrity earlier in life than other Alzheimer’s disease plasma markers: a 7T MRI study across the adult lifespan

Autopsy studies indicated that the locus coeruleus (LC) is one of the first regions to accumulate pretangle material, and imaging work demonstrated that the LC MRI‐signal correlates with entorhinal tau in cognitively normal individuals. Recently developed phosphor‐tau (ptau) blood‐based biomarkers correlated well with cortical tau‐PET and have been suggested as early markers of aberrant tau phosphorylation. Here we evaluated the relationship between LC‐MRI signal intensity and plasma markers of tau (ptau231, ptau217, ptau181), neurodegenerative processes (total tau (t‐tau), neurofilament light (NfL)) and amyloidosis (Aβ42/40).