NCT04840979

Discovery and Validation of Genetic Variants Affecting Microglial Activation in Alzheimer's Disease

Discovery and Validation of Genetic Variants Affecting Microglial Activation in Alzheimer's Disease With 11C-ER176

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 250 (estimated)
• Sponsor: Columbia University · Academic / Other
• Sex: All
• Age: 50 Years
• Healthy volunteers: Accepted

Summary

The primary objectives are to validate that a previously identified gene variant influences the proportion of activated microglia (PAM) and the amount of TSPO binding on PET imaging, to identify novel loci that influence PAM and TSPO PET, and to understand the functional consequences of gene variants that drive microglial activation in Alzheimer's disease.

Detailed description

While activated microglia have been observed in the vicinity of neuritic amyloid plaques in Alzheimer's disease (AD), there have been no large-scale assessments of microglial activation in aging and neurodegenerative disease. The investigators seek to understand the genetic underpinning of microglial responses-particularly the proportion of microglia in a morphologically-defined state of activation-that increase susceptibility to AD, so the investigators can develop more targeted forms of immune-based therapies to prevent cognitive decline and progression to dementia. The objective is to refine the genetic architecture of microglial activation to validate a previously identified gene variant -- and to identify novel loci -- that influence the proportion of activated microglia. The investigators also seek to understand the functional consequences of variants driving microglial activation in AD. The central hypothesis is that identifiable gene variants influence microglial activation and susceptibility to AD. The investigators will test this hypothesis by conducting genome-wide analysis and identifying associations between gene variants and microglial activation. Microglial activation will be measured in human autopsy tissue (ex vivo), living human brain using PET imaging (in vivo), and in monocyte-derived microglia-like cells (in situ and in vitro). This genetic study is designed to validate a finding that was discovered in participants with self-reported European-Caucasian ancestry. Therefore, the study seeks to enroll participants who self-report as white, not Hispanic or Latino. However, if this study is successful, the investigators plan to use the methods in this protocol in a future study to identify new genetic variants associated with changes on TSPO PET in a more diverse participant population. The investigators intend to use the results from this study to eventually benefit individuals of all racial and ethnic groups.

Conditions

• Alzheimer Disease

Interventions

Type	Name	Description
DRUG	11C-ER176	11C-ER176 is a novel TSPO radioligand that was developed because of its relative insensitivity to the rs6971 polymorphism. Increased TSPO signal on PET is associated with activation of microglia in the brain. The radioligand will be administered in tracer doses at activity of up to 20 mCi (740 MBq), IV, total of one injection. A single dose of radioligand will be injected over 1 minute.
DRUG	18F-florbetaben	Florbetaben has been approved by the FDA to help diagnose Alzheimer's disease. Florbetaben measures amyloid in the brain.

Timeline

• Start date: 2021-05-11
• Primary completion: 2026-12-01
• Completion: 2026-12-01
• First posted: 2021-04-12
• Last updated: 2025-04-24

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study