Study: PET with PiB can image amyloid deposits in Down syndrome
Dynamic 11C-PiB PET can be used successfully to measure cerebral beta-amyloid deposition in Down syndrome, according to a study published online March 14 in the Archives of Neurology.
The objective of the study was to investigate the safety, acceptability and feasibility of PET using carbon 11-labeled Pittsburgh Compound B (11C- PiB) to measure cerebral beta-amyloid in adults with Down syndrome and to explore if the technique differentiated between participants with and without Alzheimer's disease.
The participants included in the study involved nine with Down syndrome (aged 25 to 64 years), of whom five had a diagnosis of Alzheimer's disease, and 14 healthy controls without Down syndrome (aged 33 to 69 years).
All participants had dynamic 11C- PiB PET and magnetic resonance imaging. 11C- PiB binding in the regions of interest associated with Alzheimer's disease was quantitatively analyzed by Jennifer Landt, MSc, research assistant, Cambridge Intellectual and Developmental Disabilities Research Group, University of Cambridge, England and colleagues.
The scanning process was feasible and acceptable with no adverse events or safety concerns. When compared with the healthy control group without Down syndrome, only participants with Down syndrome older than 45 years had significant 11C- PiB binding in regions of interest usually associated with Alzheimer's disease, whether or not they had clinical evidence of dementia.
The results of the study supported the hypothesis of a “catalytic” role for amyloid such that it initiates a process whereby amyloid accumulates, reaches a steady state and then sets off a chain of events leading to synaptic dysfunction, neuronal loss and dementia, according to Landt and colleagues.
The key strength of studying Alzheimer's disease in Down syndrome is that virtually all participants with Down syndrome will be 11C- PiB positive by 50 years of age, according to Landt and colleagues. Because everyone with Down syndrome will eventually develop extensive cerebral amyloid deposits, medications that either vaccinate against or remove amyloid in its early stages could be universally administered to this high-risk group, with the possibility that the onset of clinical dementia could be prevented or at least delayed, noted the authors.
Dynamic 11C- PiB PET can be used to measure cerebral beta-amyloid deposition in Down syndrome. A clinical diagnosis of Alzheimer's disease and age appear to be predictors of 11C- PiB binding in regions of interest, but given the small numbers, Landt and colleagues said they could not generalize the results.
The objective of the study was to investigate the safety, acceptability and feasibility of PET using carbon 11-labeled Pittsburgh Compound B (11C- PiB) to measure cerebral beta-amyloid in adults with Down syndrome and to explore if the technique differentiated between participants with and without Alzheimer's disease.
The participants included in the study involved nine with Down syndrome (aged 25 to 64 years), of whom five had a diagnosis of Alzheimer's disease, and 14 healthy controls without Down syndrome (aged 33 to 69 years).
All participants had dynamic 11C- PiB PET and magnetic resonance imaging. 11C- PiB binding in the regions of interest associated with Alzheimer's disease was quantitatively analyzed by Jennifer Landt, MSc, research assistant, Cambridge Intellectual and Developmental Disabilities Research Group, University of Cambridge, England and colleagues.
The scanning process was feasible and acceptable with no adverse events or safety concerns. When compared with the healthy control group without Down syndrome, only participants with Down syndrome older than 45 years had significant 11C- PiB binding in regions of interest usually associated with Alzheimer's disease, whether or not they had clinical evidence of dementia.
The results of the study supported the hypothesis of a “catalytic” role for amyloid such that it initiates a process whereby amyloid accumulates, reaches a steady state and then sets off a chain of events leading to synaptic dysfunction, neuronal loss and dementia, according to Landt and colleagues.
The key strength of studying Alzheimer's disease in Down syndrome is that virtually all participants with Down syndrome will be 11C- PiB positive by 50 years of age, according to Landt and colleagues. Because everyone with Down syndrome will eventually develop extensive cerebral amyloid deposits, medications that either vaccinate against or remove amyloid in its early stages could be universally administered to this high-risk group, with the possibility that the onset of clinical dementia could be prevented or at least delayed, noted the authors.
Dynamic 11C- PiB PET can be used to measure cerebral beta-amyloid deposition in Down syndrome. A clinical diagnosis of Alzheimer's disease and age appear to be predictors of 11C- PiB binding in regions of interest, but given the small numbers, Landt and colleagues said they could not generalize the results.