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[O1–06–01]: REGIONAL AV1451 UPTAKE AND CORTICAL THICKNESS IN RELATION TO MEMORY, LANGUAGE AND EXECUTIVE FUNCTIONING IN AMYLOID‐POSITIVE SUBJECTS
Author(s) -
Wisse Laura E.M.,
Das Sandhitsu R.,
Xie Long,
Ittyerah Ranjit,
Yushkevich Paul A.,
Wolk David A.
Publication year - 2017
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2017.07.064
Subject(s) - psychology , dementia , cognition , temporal lobe , audiology , semantic memory , effects of sleep deprivation on cognitive performance , recall , neuroscience , pathology , medicine , disease , cognitive psychology , epilepsy
clinical data, visually evaluated amyloid-PET scans; amyloid-PET positivity was determined bymajority assessment. Intra-reader reliability was determined based on re-ratings of approximately 10% of randomly selected images from available PET scans. Interreader reliability was also assessed. SUVRs were calculated in a standardized cortical region-of-interest using whole cerebellum as the reference region. CSF samples were analyzed using Elecsys immunoassays for Ab42, tTau, and pTau. Results:Data from both ADNI and BioFINDER cohorts will be presented. For BioFINDER, intra-reader reliability based on average positive agreement (APA) and average negative agreement (ANA) was >90%. Inter-reader reliability gave an APA >80% and ANA >90%. Cut-off values for Ab42, pTau/Ab42, and tTau/Ab42 were defined based on visual-read amyloid-PET positivity. The associated positive (PPA) and negative percentage agreements (NPA) at the cut-off value were 91% and 72% for Ab42, and 91% and 89% for both pTau/Ab42 and tTau/Ab42, respectively. Higher concordance could be achieved with reference SUVR. Conclusions:We present a method to determine cut-off values of Elecsys CSF immunoassays based on visual-read amyloid-PET positivity. The Elecsys CSF immunoassays demonstrated excellent ability to predict amyloid-PET positivity, which was further improved by using tTau/ Ab42 and pTau/Ab42 ratios compared to Ab42 alone.