%0 Journal Article %J J Alzheimers Dis %D 2018 %T Concordance Between Cerebrospinal Fluid Biomarkers with Alzheimer's Disease Pathology Between Three Independent Assay Platforms. %A Doecke, James D %A Rembach, Alan %A Villemagne, Victor L %A Varghese, Shiji %A Rainey-Smith, Stephanie %A Sarros, Shannon %A Evered, Lisbeth A %A Fowler, Christopher J %A Pertile, Kelly K %A Rumble, Rebecca L %A Trounson, Brett %A Taddei, Kevin %A Laws, Simon M %A Macaulay, S Lance %A Bush, Ashley I %A Ellis, Kathryn A %A Martins, Ralph %A Ames, David %A Silbert, Brendan %A Vanderstichele, Hugo %A Masters, Colin L %A Darby, David G %A Li, Qiao-Xin %A Collins, Steven %K Aged %K Aged, 80 and over %K Alzheimer Disease %K Amyloid beta-Peptides %K Biomarkers %K Cognition Disorders %K Female %K Humans %K Male %K Mental Status Schedule %K Peptide Fragments %K Positron-Emission Tomography %K ROC Curve %K tau Proteins %X

BACKGROUND: To enhance the accuracy of clinical diagnosis for Alzheimer's disease (AD), pre-mortem biomarkers have become increasingly important for diagnosis and for participant recruitment in disease-specific treatment trials. Cerebrospinal fluid (CSF) biomarkers provide a low-cost alternative to positron emission tomography (PET) imaging for in vivo quantification of different AD pathological hallmarks in the brains of affected subjects; however, consensus around the best platform, most informative biomarker and correlations across different methodologies are controversial.

OBJECTIVE: Assessing levels of Aβ-amyloid and tau species determined using three different versions of immunoassays, the current study explored the ability of CSF biomarkers to predict PET Aβ-amyloid (32 Aβ-amyloid-and 45 Aβ-amyloid+), as well as concordance between CSF biomarker levels and PET Aβ-amyloid imaging.

METHODS: Prediction and concordance analyses were performed using a sub-cohort of 77 individuals (48 healthy controls, 15 with mild cognitive impairment, and 14 with AD) from the Australian Imaging Biomarker and Lifestyle study of aging.

RESULTS: Across all three platforms, the T-tau/Aβ42 ratio biomarker had modestly higher correlation with SUVR/BeCKeT (ρ= 0.69-0.8) as compared with Aβ42 alone (ρ= 0.66-0.75). Differences in CSF biomarker levels between the PET Aβ-amyloid-and Aβ-amyloid+ groups were strongest for the Aβ42/Aβ40 and T-tau/Aβ42 ratios (p < 0.0001); however, comparison of predictive models for PET Aβ-amyloid showed no difference between Aβ42 alone and the T-tau/Aβ42 ratio.

CONCLUSION: This study confirms strong concordance between CSF biomarkers and PET Aβ-amyloid status is independent of immunoassay platform, supporting their utility as biomarkers in clinical practice for the diagnosis of AD and for participant enrichment in clinical trials.

%B J Alzheimers Dis %V 61 %P 169-183 %8 2018 %G eng %N 1 %1 http://www.ncbi.nlm.nih.gov/pubmed/29171991?dopt=Abstract %R 10.3233/JAD-170128 %0 Journal Article %J J Alzheimers Dis %D 2016 %T Subjective Memory Complaints in APOEɛ4 Carriers are Associated with High Amyloid-β Burden. %A Zwan, Marissa D %A Villemagne, Victor L %A Doré, Vincent %A Buckley, Rachel %A Bourgeat, Pierrick %A Veljanoski, Robyn %A Salvado, Olivier %A Williams, Rob %A Margison, Laura %A Rembach, Alan %A Macaulay, S Lance %A Martins, Ralph %A Ames, David %A van der Flier, Wiesje M %A Ellis, Kathryn A %A Scheltens, Philip %A Masters, Colin L %A Rowe, Christopher C %K Aged %K Aging %K Amyloid beta-Peptides %K Aniline Compounds %K Apolipoprotein E4 %K Benzothiazoles %K Brain %K Cognition Disorders %K Female %K Genotyping Techniques %K Heterozygote %K Humans %K Logistic Models %K Male %K Neuropsychological Tests %K Positron-Emission Tomography %K Radiopharmaceuticals %K Thiazoles %X

BACKGROUND: APOEɛ4 genotype and aging have been identified as risk factors for Alzheimer's disease (AD). In addition, subjective memory complaints (SMC) might be a first clinical expression of the effect of AD pathology on cognitive functioning.

OBJECTIVE: To assess whether APOEɛ4 genotype, age, SMC, and episodic memory are risk factors for high amyloid-β (Aβ) burden in cognitively normal elderly.

METHODS: 307 cognitively normal participants (72.7 ± 6.8 years, 53% female, 55% SMC) from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study underwent amyloid PET and APOE genotyping. Logistic regression analyses were performed to determine the association of APOEɛ4 genotype, age, SMC, and episodic memory with Aβ pathology.

RESULTS: Odds of high Aβ burden were greater at an older age (OR = 3.21; 95% CI = 1.68-6.14), when SMC were present (OR = 1.90; 95% CI = 1.03-3.48), and for APOEɛ4 carriers (OR = 7.49; 95% CI = 3.96-14.15), while episodic memory was not associated with odds of high Aβ burden. Stratified analyses showed that odds of SMC for high Aβ burden were increased in specifically APOEɛ4 carriers (OR = 4.58, 95% CI = 1.83-11.49) and younger participants (OR = 3.73, 95% CI = 1.39-10.01).

CONCLUSION: Aging, APOEɛ4 genotype, and SMC were associated with high Aβ burden. SMC were especially indicative of high Aβ burden in younger participants and in APOEɛ4 carriers. These findings suggest that selection based on the presence of SMC, APOEɛ4 genotype and age may help identify healthy elderly participants with high Aβ burden eligible for secondary prevention trials.

%B J Alzheimers Dis %V 49 %P 1115-22 %8 2016 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/26639956?dopt=Abstract %R 10.3233/JAD-150446