Converging evidence indicates that clusterin, a chaperone glycoprotein, influences Alzheimer's disease (AD) neurodegeneration. However, the precise role of clusterin in AD pathogenesis is still not well understood.
To elucidate the relationship between clusterin, amyloid-β (Aβ), p-tau, and rate of brain atrophy over time among non-demented older individuals.
A longitudinal cohort of cognitively normal older participants (HC) and individuals with mild cognitive impairment (MCI) assessed with baseline lumbar puncture and longitudinal structural MRI.
Research centers across the United States and Canada.
We examined 241 non-demented older individuals (91 participants with a Clinical Dementia Rating (CDR) of 0 and 150 individuals with a CDR of 0.5).
Main Outcome Measures
Using linear mixed effects models, we investigated interactions between CSF clusterin, CSF Aβ1-42 and CSF p-tau181p on atrophy rate of the entorhinal cortex and hippocampus.
Across all participants, we found a significant interaction between CSF clusterin and CSF Aβ1-42 on entorhinal cortex atrophy rate, but not on hippocampal atrophy rate. CSF clusterin was associated with entorhinal cortex atrophy rate among CSF Aβ1-42 positive individuals, but not among CSF Aβ1-42 negative individuals. In secondary analyses, we found significant interactions between CSF Aβ1-42 and CSF clusterin and CSF Aβ1-42 and CSF p-tau181p on entorhinal cortex atrophy rate. We found similar results in subgroup analyses within the MCI and HC cohorts.
Conclusions and Relevance
In non-demented older individuals, Aβ-associated volume loss occurs in the presence of elevated clusterin. The effect of clusterin on Aβ-associated brain atrophy is not confounded or explained by p-tau. These findings implicate a potentially important role for clusterin in the earliest stages of the AD neurodegenerative process and suggest independent effects of clusterin and p-tau on Aβ-associated volume loss.