Biomarkers

Area of Science:

• Neurology
• Neuroimaging
• Biomarkers

Background:

• Cerebral amyloid angiopathy (CAA) diagnosis is crucial for Alzheimer's disease (AD) patients undergoing anti-amyloid immunotherapy due to its association with amyloid-related imaging abnormalities.
• The Boston criteria are standard for identifying probable CAA in memory clinics, but its prevalence and characteristics in cognitively impaired AD patients are not well-defined.

Purpose of the Study:

• To determine the prevalence of CAA in cognitively impaired, biomarker-confirmed AD patients using the updated Boston criteria (v2.0).
• To compare cognitive, clinical, and biomarker profiles between AD patients with and without CAA.

Main Methods:

• Retrospective analysis of 415 patients with probable AD (biomarker-confirmed) from a memory center database (June 2012 - July 2024).
• MRI scans were reviewed by a radiologist and image analyst (blinded to clinical data), with diagnoses confirmed by a neurologist.
• Patients were classified as high (AD-CAA) or low (AD-nCAA) probability for CAA using Boston criteria; characteristics were compared using statistical tests.

Main Results:

• 29% of AD patients were classified as AD-CAA, while 71% were AD-nCAA.
• Cognitive severity, global cognition, verbal episodic memory, and executive functions were comparable between AD-CAA and AD-nCAA groups.
• AD-CAA patients were older, more likely to use antiplatelet therapy, and had higher cardiovascular disease prevalence, but similar cardiovascular risk factors and AD biomarker profiles.

Conclusions:

• The prevalence of CAA in AD patients identified via Boston criteria was lower than pathology-based estimates.
• AD patients in memory clinics may present similar cognitive profiles and AD biomarker patterns irrespective of their CAA probability.
• Further research is essential to validate the application of the Boston criteria in memory clinic populations with AD.