Comparative analytical performance of multiple plasma Aβ42 and Aβ40 assays and their ability to predict positron emission tomography amyloid positivity

INTRODUCTION: This report details the approach taken to providing a dataset allowing for analyses on the performance of recently developed assays of amyloid beta (Aβ) peptides in plasma and the extent to which they improve the prediction of amyloid positivity. METHODS: Alzheimer's Disease Neuroimaging Initiative plasma samples with corresponding amyloid positron emission tomography (PET) data were run on six plasma Aβ assays. Statistical tests were performed to determine whether the plasma Aβ measures significantly improved the area under the receiver operating characteristic curve for predicting amyloid PET status compared to age and apolipoprotein E (APOE) genotype. RESULTS: The age and APOE genotype model predicted amyloid status with an area under the curve (AUC) of 0.75. Three assays improved AUCs to 0.81, 0.81, and 0.84 (P < .05, uncorrected for multiple comparisons). DISCUSSION: Measurement of Aβ in plasma contributes to addressing the amyloid component of the ATN (amyloid/tau/neurodegeneration) framework and could be a first step before or in place of a PET or cerebrospinal fluid screening study. HIGHLIGHTS: The Foundation of the National Institutes of Health Biomarkers Consortium evaluated six plasma amyloid beta (Aβ) assays using Alzheimer's Disease Neuroimaging Initiative samples. Three assays improved prediction of amyloid status over age and apolipoprotein E (APOE) genotype. Plasma Aβ42/40 predicted amyloid positron emission tomography status better than Aβ42 or Aβ40 alone

Disclosure of individual research results at federally funded Alzheimer’s Disease Research Centers

IntroductionThis study describes practices for disclosing individual research results to participants in Alzheimer’s disease research.MethodsAn online survey of clinical core leaders at National Institutes of Health‐funded Alzheimer’s Disease Research Centers in the United States (response rate: 30/31, 97%) examined return of results practices across nine different types of research results.ResultsMost centers had returned consensus research diagnoses (83%) and neuropsychological test results (73%), with fewer having shared amyloid positron emission tomography (43%), tau imaging (10%), or apolipoprotein E (APOE) genotype (7%) results. Centers reported having disclosed a mean of 3.1 types of results (standard deviation = 2.1; range 0–8). The most commonly cited reason for disclosure was to inform participants’ medical decision‐making (88%). Disclosure involved multiple professionals and modalities, with neurologists (87%) and in‐person visits (85%) most commonplace.DiscussionCenters varied widely as to whether and how they disclosed research results. Diagnostic and cognitive test results were more commonly returned than genetic or biomarker results.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/170878/1/trc212213.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/170878/2/trc212213_am.pd

Disclosure of individual research results at federally funded Alzheimer's Disease Research Centers

IntroductionThis study describes practices for disclosing individual research results to participants in Alzheimer's disease research.MethodsAn online survey of clinical core leaders at National Institutes of Health-funded Alzheimer's Disease Research Centers in the United States (response rate: 30/31, 97%) examined return of results practices across nine different types of research results.ResultsMost centers had returned consensus research diagnoses (83%) and neuropsychological test results (73%), with fewer having shared amyloid positron emission tomography (43%), tau imaging (10%), or apolipoprotein E (APOE) genotype (7%) results. Centers reported having disclosed a mean of 3.1 types of results (standard deviation&nbsp;=&nbsp;2.1; range 0-8). The most commonly cited reason for disclosure was to inform participants' medical decision-making (88%). Disclosure involved multiple professionals and modalities, with neurologists (87%) and in-person visits (85%) most commonplace.DiscussionCenters varied widely as to whether and how they disclosed research results. Diagnostic and cognitive test results were more commonly returned than genetic or biomarker results