Imaging Inflammation in Alzheimer's Disease

Study Overview
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Brief Summary
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This study is being done to learn about inflammation and amyloid in Alzheimer's disease. A type of brain scan called a PET scan is used measure 1) inflammation and 2) abnormal accumulation of a the amount of a certain protein fragment called beta-amyloid (plaques) in the brain. These are thought to be involved in Alzheimer's disease. The investigators will also perform brain MRI and do tests to measure the participants' memory and thinking.

Detailed Description
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This study is being done to determine the relationship between inflammation, cognitive impairment, and amyloid burden in elderly subjects with different clinical and biomarker profiles of Alzheimer's disease (AD). Participants will undergo amyloid PET imaging with 18F-Florbetaben with target number of completers being 15 amyloid-positive elders with impairment, 15 amyloid-positive elders with normal cognition, 15 amyloid-negative elders with impairment, and 15 amyloid-negative elders with normal cognition. Subjects will undergo screen that includes neuropsychological testing, brain MRI, and PET imaging with 18F-florbetaben to define the above 4 groups. Subjects will have 11C-PBR28 PET imaging to measure the 18 kDa translocator protein (a marker of inflammation). Subjects will have the option to have lumbar puncture performed to measure CSF concentrations of amyloid,tau, phospho-tau, and inflammatory markers.

Official Title
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Imaging Inflammation in Elders With Different Clinical and Biomarker Profiles of Alzheimer's Disease

Conditions
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Alzheimer's Disease

Intervention / Treatment
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* Drug: 11C-PBR28
* Drug: 18F-Florbetaben
* Procedure: Lumbar puncture (optional)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 60 and older. Meet criteria for either a) amnestic mild cognitive impairment (single or mixed domain) or mild Alzheimer's disease, or b) have no cognitive impairment based on history, exam, neuropsychological testing, and consensus diagnosis. MCI and mild AD patients must have Clinical Dementia Rating scale score of 0.5 or 1. Unimpaired subjects must have Clinical Dementia Rating scale score of 0. Subjects unable to provide informed consent must have a surrogate decision maker Written and oral fluency in English or Spanish. Able to participate in all scheduled evaluations and to complete all required tests and procedures. In the opinion of the investigator, the subject must be considered likely to comply with the study protocol and to have a high probability of completing the study. Exclusion Criteria: Past or present history of certain brain disorders other than MCI or AD. Certain significant medical conditions, which make study procedures of the current study unsafe. Contraindication to MRI scanning. Conditions precluding entry into the scanners (e.g., morbid obesity, claustrophobia, etc.). Exposure to research related radiation in the past year that, when combined with this study, would place subjects above the allowable limits. Low affinity binding on TSPO genetic screen. Participation in the last year in a clinical trial for a disease modifying drug for AD. Inability to have a catheter in subject's vein for the injection of radioligand. Inability to have blood drawn from subject's veins.

Ages Eligible for Study
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Minimum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cognitive impairment<br>Alzheimer's disease, Preclinical Alzheimer's disease or Impairment due to suspected non-Alzheimer's disease pathophysiology | Drug: 11C-PBR28<br>* 11C-PBR28 is a PET radioligand that binds to the 18 kDa translocator protein (TSPO), a marker of inflammation. 11C-PBR28 has previously been administered in humans. 11C-PBR28 will be administered at activity of up to 20 mCi per injection.<br>* Other names: 11C-[O-methyl-11C]N-acetyl-N-(2-methoxybenzyl)-2-phenoxy-5-pyridinamine;Drug: 18F-Florbetaben<br>* 18F-Florbetaben (Neuraceq) has FDA approval for human use in evaluation of Alzheimer's disease. 18F-Florbetaben will be administered at activity up to 8.1 mCi per injection.<br>* Other names: Neuraceq;Procedure: Lumbar puncture (optional)<br>* Subjects have the option to have lumbar puncture performed for the measurement of inflammatory markers in cerebrospinal fluid.<br>* Other names: LP;|
| Active Comparator: No cognitive impairment<br>Normal aging | Drug: 11C-PBR28<br>* 11C-PBR28 is a PET radioligand that binds to the 18 kDa translocator protein (TSPO), a marker of inflammation. 11C-PBR28 has previously been administered in humans. 11C-PBR28 will be administered at activity of up to 20 mCi per injection.<br>* Other names: 11C-[O-methyl-11C]N-acetyl-N-(2-methoxybenzyl)-2-phenoxy-5-pyridinamine;Drug: 18F-Florbetaben<br>* 18F-Florbetaben (Neuraceq) has FDA approval for human use in evaluation of Alzheimer's disease. 18F-Florbetaben will be administered at activity up to 8.1 mCi per injection.<br>* Other names: Neuraceq;Procedure: Lumbar puncture (optional)<br>* Subjects have the option to have lumbar puncture performed for the measurement of inflammatory markers in cerebrospinal fluid.<br>* Other names: LP;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 11C-PBR28 binding (standardized uptake value ratio) | In vivo quantification radioligand binding to TSPO expression on microglia in the brain. | Up to 1 year from screening | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 18F-Florbetaben binding (standardized uptake value ratio) | In vivo quantification of radioligand binding to Amyloid-Beta protein in the brain. | Up to 1 year from screening | 
| Cerebral spinal fluid (CSF) biomarkers | Protein analysis of cerebral spinal fluid. | Up to 1 year from screening | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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inflammation, aging, mild cognitive impairment