There are currently no practical biomarkers for Alzheimer?s Disease (AD) that can routinely stage, assess prognosis, and monitor treatment response. AD is a complex disease of overlapping pathophysiologies that lead to eventual synapse loss and progressive dementia. The core AD biomarkers, amyloid-b and tau (total and phospho-) measured in cerebrospinal fluid (CSF), provide a strong indication of the presence or absence of substantial AD pathology, but as yet poorly reflect disease stage or progression. In order to diagnose the disease earlier, learn about the time-course of concurrent pathophysiologies, and maximize the potential for staging, tracking and treatment, it is critical that more useful AD biomarkers are characterized. A collaboration is proposed between the Yale and Massachusetts ADRCs that will leverage the individual strengths of these two centers to discover pathway driven novel biomarkers of AD. Using the large numbers of clinically characterized biofluid samples available from the Massachusetts ADRC, the Yale ADRC will employ their expertise in quantitative targeted LC- MS/MS technology to assess over one hundred analytes in CSF, with an extension of the most informative to blood. LC-MS/MS is inherently specific, and enables simultaneous testing of many markers from a small biofluid volume. Use of Data-Independent-Acquisition (DIA) LC- MS/MS techniques allows for primary data to be reanalyzed for retrospective analysis of new biomarkers, providing a reproducible yet flexible discovery pipeline.
In Aim 1, a panel of over 100 proteins in CSF from pathways involved in AD pathophysiology will be subjected to comprehensive technical qualification. Using samples from the placebo arm of a clinical trial, peptides will be tested for linearity, inter-assay, intra-assay and short term biotemporal stability. All high performing peptides will then be quantified in a high contrast sample of 60 Cognitively unimpaired-adults (CU-A) and 60 dementia due to AD cases. They will be assessed for their ability to distinguish AD from CU-A, and for their correlation with markers of synaptic function.
In Aim 2, technically qualified peptides will be quantified in 3 tailored sample collections to assess their performance in AD staging, prognosis and differential diagnosis.
In Aim 3, the most informative analytes from Aims 1 & 2 will be quantified in blood, either by LC-MS/MS, or by sensitive or ultra-sensitive ELISA approaches. Peptide abundance will be compared across biofluids, and the diagnostic utility of these markers in blood assessed.

Public Health Relevance

Alzheimer?s Disease is a complex disease for which there is a need for sensitive and specific biomarkers for predicting disease progression and stage. We propose a collaboration between the Massachusetts and Yale Alzheimer?s Disease Research Centers to develop a flexible and reproducible mass-spectrometry biomarker discovery pipeline for cerebrospinal fluid and plasma. By focusing on measurement of biological pathways relevant to synaptic dysfunction in Alzheimer?s Disease, we hope to identify clinically useful biomarkers that will also offer mechanistic insights into disease pathophysiology and progression.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG062306-03
Application #
9936307
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Silverberg, Nina B
Project Start
2018-09-30
Project End
2023-05-31
Budget Start
2020-06-01
Budget End
2021-05-31
Support Year
3
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Massachusetts General Hospital
Department
Type
DUNS #
073130411
City
Boston
State
MA
Country
United States
Zip Code
02114