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P2‐043: A quantitative assay selective for amyloid oligomer species differentiates cerebrospinal fluid from Alzheimer's disease and age‐matched normal
Author(s) -
Wolfe Abigail,
McCampbell Alexander,
Hatcher Nate,
Tugusheva Katherine,
Haugabook Sharie,
Maxwell Jill,
Wu Guoxin,
Howell Bonnie,
Renger John,
Shughrue Paul,
Savage Mary
Publication year - 2012
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.2012.05.746
Subject(s) - oligomer , chemistry , monoclonal antibody , monomer , antibody , cerebrospinal fluid , amyloid beta , alzheimer's disease , detection limit , microbiology and biotechnology , selectivity , chromatography , biochemistry , pathology , peptide , medicine , immunology , biology , disease , polymer chemistry , polymer , organic chemistry , catalysis
Visual contrast sensitivity was assessed separately for both eyes using the FDT-2 (Welch Allyn, Syracuse, NY) in 55 visual field regions (Fig. 1). Classification was assessed using: (1) 6 overall measures detailing alternations in contrast sensitivity ("bilateral" pattern standard deviation (PSD), test duration (TDur), and mean deviation (MDev)), and (2) 110 threshold measures from 55 visual field regions of each eye. All measures were pre-adjusted for age, gender and education (see [2] for further details). Elastic net [3] was used to differentiate the following pairs of groups: HC/CC, HC/MCI, HC/AD, CC/MCI, CC/AD, and MCI/AD. Leave-one-out cross validation was employed for accuracy estimation. Results: FDT measures demonstrated promising potential (Table 1(a)) in differentiating AD from HC (84.2%), CC (75.9%) and MCI (81.1%), and some ability to distinguish HC from CC (59.2%) and MCI (68.4%). The overall measures performed better in classifying HC fromMCI and AD, while the regionalmeasures better distinguished AD from CC and MCI. The relative importance of each measure in classification is shown in Table 1(b) for overall measures and in Fig. 1 for regional measures.Conclusions:Visual contrast sensitivity shows potential as a novel biomarker to classify early and preclinical stages of AD. Advanced multivariate classification methods appear promising to enhance accuracy, automate analysis, and may yield insights into specific visual system regions and biological processes. Future studies are needed to address pattern analysis of longitudinal changes. References: [1] Risacher et al. Alzheimer’s and Dementia (2010). [2] Risacher, Indiana University (2011). [3] Friedman et al. J Stat Softw (2010).