PET Imaging Determines β-Amyloid Levels

January 24, 2011

Florbetapir F 18 positron emission tomography (PET) appears to be an effective method for determining β-amyloid levels in vivo, and lower levels of β-amyloid in older adults may predict greater cognitive decline as they age, according to two articles published in the Jan. 19 issue of the Journal of the American Medical Association.

HealthDay News -- Florbetapir F 18 positron emission tomography (PET) appears to be an effective method for determining β-amyloid levels in vivo, and lower levels of β-amyloid in older adults may predict greater cognitive decline as they age, according to two articles published in the Jan. 19 issue of the Journal of the American Medical Association.

Christopher M. Clark, M.D., of Avid Radiopharmaceuticals in Philadelphia, and colleagues performed florbetapir-PET imaging on 35 patients near the end of life to determine the accuracy of the method for predicting the presence of β-amyloid in brain tissue after death. They found florbetapir-PET imaging correlated with the presence and density of β-amyloid, and that florbetapir-PET images and postmortem results were in agreement in 96 percent of the primary analysis cohort.

Kristine Yaffe, M.D., of the University of California in San Francisco, and colleagues studied 997 older adults in a community setting to assess the relationship between plasma β-amyloid levels and cognitive decline and whether cognitive reserve modifies that association. They found that low β-amyloid 42/40 levels were associated with greater nine-year cognitive decline in individuals without dementia, particularly in those with lower measures of cognitive reserve (e.g., those with less than a high school education).

"Future studies should further explore the use of plasma β-amyloid as a biomarker, assess the mechanisms by which cognitive reserve modifies this association, and determine whether increasing cognitive reserve through interventions can reduce the risk of Alzheimer's disease," Yaffe and colleagues conclude.

Several authors of the first article disclosed financial relationships with medical device and/or pharmaceutical companies, including Avid Radiopharmaceuticals Inc., which provided funding for the research.

Abstract - ClarkFull Text (subscription or payment may be required)
Abstract - YaffeFull TextEditorial (subscription or payment may be required)

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