Amyloid-beta plaque growth in cognitively normal adults: longitudinal [11C]Pittsburgh compound B data.

ABSTRACT: Amyloid-beta (A?) accumulation was evaluated with 2 [(11)C]Pittsburgh compound B (PiB) positron emission tomography scans about 2.5 years apart in 146 cognitively normal adults. Seventeen of 21 participants with initially elevated A? deposition demonstrated subsequent A? plaque growth (approximately 8.0% per year), and none reverted to a state of no A? deposits. Ten individuals converted from negative to positive PiB status, based on a threshold of the mean cortical binding potential, representing a conversion rate of 3.1% per year. Individuals with an ?4 allele of apolipoprotein E demonstrated increased incidence of conversion (7.0% per year). Our findings suggest that the major growth in A? burden occurs during a preclinical stage of Alzheimer disease (AD), prior to the onset of AD-related symptoms.

SUBMITTER: Vlassenko AG 

PROVIDER: S-EPMC3243969 | biostudies-other | 2011 Nov

REPOSITORIES: biostudies-other