Open AccessUsing florbetapir positron emission tomography to explore cerebrospinal fluid cut points and gray zones in small sample sizes
Author(s) -
Weston Philip S.J.,
Paterson Ross W.,
Modat Marc,
Burgos Ni,
Cardoso Manuel J.,
Magdalinou Nadia,
Lehmann Manja,
Dickson John C.,
Barnes Anna,
Bomanji Jamshed B.,
Kayani Irfan,
Cash David M.,
Ourselin Sebastien,
Toombs Jamie,
Lunn Michael P.,
Mummery Catherine J.,
Warren Jason D.,
Rossor Martin N.,
Fox Nick C.,
Zetterberg Henrik,
Schott Jonathan M.
Publication year - 2015
Publication title -
alzheimer's and dementia: diagnosis, assessment and disease monitoring
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.497
H-Index - 37
ISSN - 2352-8729
DOI - 10.1016/j.dadm.2015.10.001
Subject(s) - cerebrospinal fluid , positron emission tomography , concordance , nuclear medicine , medicine , pathology , amyloid (mycology) , standardized uptake value , β amyloid , amyloid β , alzheimer's disease , disease
We aimed to assess the feasibility of determining Alzheimer's disease cerebrospinal fluid (CSF) cut points in small samples through comparison with amyloid positron emission tomography (PET). Methods Twenty‐three individuals (19 patients, four controls) had CSF measures of amyloid beta (Aβ) 1–42 and total tau/Aβ 1–42 ratio, and florbetapir PET. We compared CSF measures with visual and quantitative (standardized uptake value ratio [SUVR]) PET measures of amyloid. Results Seventeen of 23 were amyloid‐positive on visual reads, and 14 of 23 at an SUVR of ≥1.1. There was concordance (positive/negative on both measures) in 20 of 23, of whom 19 of 20 were correctly classified at an Aβ 1–42 of 630 ng/L, and 20 of 20 on tau/Aβ 1–42 ratio (positive ≥0.88; negative ≤0.34). Three discordant cases had Aβ 1–42 levels between 403 and 729 ng/L and tau/Aβ 1–42 ratios of 0.54–0.58. Discussion Comparing amyloid PET and CSF biomarkers provides a means of assessing CSF cut points in vivo, and can be applied to small sample sizes. CSF tau/Aβ 1–42 ratio appears robust at predicting amyloid status, although there are gray zones where there remains diagnostic uncertainty.