Please use this identifier to cite or link to this item:
Title: Assessing Reactive Astrogliosis with 18F-SMBT-1 Across the Alzheimer Disease Spectrum.
Austin Authors: Villemagne, Victor L ;Harada, Ryuichi;Doré, Vincent ;Furumoto, Shozo;Mulligan, Rachel S ;Kudo, Yukitsuka;Burnham, Samantha;Krishnadas, Natasha ;Bourgeat, Pierrick;Xia, Ying;Laws, Simon;Bozinovski, Svetlana ;Huang, Kun ;Ikonomovic, Milos D;Fripp, Jürgen;Yanai, Kazuhiko;Okamura, Nobuyuki;Rowe, Christopher C 
Affiliation: The Florey Institute of Neuroscience and Mental Health
CSIRO Health and Biosecurity Flagship: Australian e-Health Research Centre, Melbourne, Victoria, Australia
School of Medical and Health Sciences, Edith Cowan University, Perth, Western Australia, Australia
CSIRO: Australian e-Health Research Centre, Brisbane, Queensland, Australia
Department of Molecular Imaging and Therapy, Austin Health, Melbourne, Victoria, Australia
Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania.
Australian Dementia Network, Melbourne, Victoria, Australia
Department of Pharmacology, School of Medicine, Tohoku University, Sendai, Japan.
Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan.
Institute of Development of Aging and Cancer, Tohoku University, Sendai, Japan.
Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan.
Medicine (University of Melbourne)
Issue Date: Oct-2022
Date: 2022
Publication information: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine 2022; 63(10): 1560-1569
Abstract: A neuroinflammatory reaction in Alzheimer disease (AD) brains involves reactive astrocytes that overexpress monoamine oxidase-B (MAO-B). 18F-(S)-(2-methylpyrid-5-yl)-6-[(3-fluoro-2-hydroxy)propoxy]quinoline (18F-SMBT-1) is a novel 18F PET tracer highly selective for MAO-B. We characterized the clinical performance of 18F-SMBT-1 PET across the AD continuum as a potential surrogate marker of reactive astrogliosis. Methods: We assessed 18F-SMBT-1 PET regional binding in 77 volunteers (76 ± 5.5 y old; 41 women, 36 men) across the AD continuum: 57 who were cognitively normal (CN) (44 amyloid-β [Aβ]-negative [Aβ-] and 13 Aβ-positive [Aβ+]), 12 who had mild cognitive impairment (9 Aβ- and 3 Aβ+), and 8 who had AD dementia (6 Aβ+ and 2 Aβ-). All participants also underwent Aβ and tau PET imaging, 3-T MRI, and neuropsychologic evaluation. Tau imaging results were expressed in SUV ratios using the cerebellar cortex as a reference region, whereas Aβ burden was expressed in centiloids. 18F-SMBT-1 outcomes were expressed as SUV ratio using the subcortical white matter as a reference region. Results: 18F-SMBT-1 yielded high-contrast images at steady state (60-80 min after injection). When compared with the Aβ- CN group, there were no significant differences in 18F-SMBT-1 binding in the group with Aβ- mild cognitive impairment. Conversely, 18F-SMBT-1 binding was significantly higher in several cortical regions in the Aβ+ AD group but also was significantly lower in the mesial temporal lobe and basal ganglia. Most importantly, 18F-SMBT-1 binding was significantly higher in the same regions in the Aβ+ CN group as in the Aβ- CN group. When all clinical groups were considered together, 18F-SMBT-1 correlated strongly with Aβ burden and much less with tau burden. Although in most cortical regions 18F-SMBT-1 did not correlate with brain volumetrics, regions known for high MAO-B concentrations presented a direct association with hippocampal and gray matter volumes, whereas the occipital lobe was directly associated with white matter hyperintensity. 18F-SMBT-1 binding was inversely correlated with Mini Mental State Examination and the Australian Imaging Biomarkers and Lifestyle's Preclinical Alzheimer Cognitive Composite in some neocortical regions such as the frontal cortex, lateral temporal lobe, and supramarginal gyrus. Conclusion: Cross-sectional human PET studies with 18F-SMBT-1 showed that Aβ+ AD patients, but most importantly, Aβ+ CN individuals, had significantly higher regional 18F-SMBT-1 binding than Aβ- CN individuals. Moreover, in several regions in the brain, 18F-SMBT-1 retention was highly associated with Aβ load. These findings suggest that increased 18F-SMBT-1 binding is detectable at the preclinical stages of Aβ accumulation, providing strong support for its use as a surrogate marker of astrogliosis in the AD continuum.
DOI: 10.2967/jnumed.121.263255
Journal: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
PubMed URL: 35086892
Type: Journal Article
Subjects: Alzheimer disease
brain imaging
reactive astrogliosis
Appears in Collections:Journal articles

Show full item record

Page view(s)

checked on Sep 29, 2023

Google ScholarTM


Items in AHRO are protected by copyright, with all rights reserved, unless otherwise indicated.