Amyloid Imaging with Florbetapir F 18 (18 F-AV-45) PET in a subject with Down's Syndrome and Alzheimer's disease at the End of Life

• Published in: Alzheimer's & dementia Vol. 6; no. 4; p. S24
• Main Authors: Sabbagh, Marwan N, Jacobson, Sandra A, Sue, Lucia I, Liebsack, Carolyn, Charney, Albert S, Beach, Thomas G
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.07.2010
• Subjects: Alzheimer's disease; Comorbidity; Cortex; Down's syndrome; Imaging; Neurology
• ISSN: 1552-5260; 1552-5279
• DOI: 10.1016/j.jalz.2010.05.068

Background: Molecular imaging of amyloid deposition in vivo may improve clinical diagnostic accuracy. Florbetapir is under development as a candidate amyloid PET biomarker with adequate performance characteristics to correlate PET images with histopathological findings at autopsy. Since Down's syndrome (DS) patients develop Alzheimer's disease (AD), amyloid imaging could be used to detect AD pathology in DS. We report imaging with florbetapir F 18 PET assess cortical Beta-amyloid deposition in a DS subject with AD proximate to death. Methods: A 55 year old subject with DS presented 5 years prior to death with progressive cognitive decline. Given the low baseline function, the decline was documented from family members by progressive loss of IADLs and ADLs. Eventually, the subject was non-testable and the last MMSE was recorded as 0. The subject was enrolled in the florbetapir histopathology study. The subject received a 10 minute PET image after iv injection of 10 mCi (370 MBq) of florbetapir. Each image was rated visually using a semi-qualitative scale (0 - 4) for overall ligand retention in cortical gray matter. Independently a semi-automated algorithm calculated standard uptake values (SUV) in pre-defined anatomically relevant cortical regions, relative to cerebellar gray matter (SUVr). The subject expired 14 days after imaging. The brain was collected at autopsy for neuropathological analysis. Neuropathologic studies are blinded to the clinical and PET data. Results: Visual ratings of the intensity of florbetapir signal across the 6 PET scans ranged from 0 (no amyloid) to 4 (maximal amyloid). There was moderate uptake of florbetapir in the frontal cortex and mild uptake in the occipital and white matter. There was minimal or no uptake in the temporal and parietal cortices by visual inspection. The co-registered CT revealed underlying atrophy and ex vacuo changes to the ventricles. Autopsy results and correlation to imaging findings will be presented. Conclusions: This is the first report of florbetapir imaging in a DS/AD subject. Since the images were gathered proximate to death, there is an opportunity to correlate imaging findings with pathological features at autopsy. Molecular imaging with florbetapir could provide important information about brain Beta-amyloid deposition in cortical gray matter in advanced dementia. [Copyright Elsevier B.V.]