- Email: [email protected]
CENTILOID THRESHOLDS FOR AMYLOID POSITIVITY DERIVED FROM AUTOPSY-PROVEN CASES
Poster Presentations: Monday, July 25, 2016
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hippocampus in 24-month-old rats than in that 12-month-old rats in mild stress. These data are characterised by increase number of hyperchromatic neurons and increase of iNOS and eNOS expression in perikaria of pyramidal neurons, at the same time it was found reducing eNOS expression in microvascular endothelium. These changes are accompanied by more severe cognitive disorders in 24-month-old rats which may accelerate the process of aging. *This investigation was supported by grant of Volgograd State Medical University. P2-284
LIPOPOLYSACCHARIDE AND E. COLI PROTEINS AND DNA IN ALZHEIMER’S DISEASE BRAINS COMPARED TO CONTROLS
Xinhua Zhan1, Boryana Stamova1, Lee-Way Jin2, Charles DeCarli3, Brett Phinney4, Frank R. Sharp1, 1University of California Davis, Sacramento, CA, USA; 2UC Davis, Davis, CA, USA; 3University of California Davis, Davis, CA, USA; 4University of California at Davis, Davis, CA, USA. Contact e-mail: [email protected] Background: Amyloid plaques in Alzheimer’s disease (AD) are believed to be derived in part from clevage products of amyloid precursor protein (APP). However, Gram-negative Escherichia coli (E. coli) bacteria and other microorganisms can form extracellular amyloid. Moreover, administration of Gram-negative bacterial derived Lipopolysaccharide (LPS) followed by ischemia and hypoxia produce plaque-like aggregates of myelin and amyloid ß in adult rat brains. These findings led us to examine human brain for LPS and E. coli proteins and DNA. Methods: Brain samples from superior temporal gyrus gray matter and frontal lobe white matter were studied from AD patients (n¼24) and age-matched controls (n¼18). LPS and E. coli proteins including K99 pili protein were evaluated by Western blots and immunocytochemistry. DNA from human brains was assessed for E. coli DNA. Results: LPS and E. coli K99 were detected immunocytochemically in brain parenchyma and vessels in all AD and control brains. K99 levels by Western blots were greater in AD compared to control brains (p < 0.01) and K99 was localized to neurons in AD but not control brains. LPS co-localized with Aß1-40/42 in amyloid plaques and with Aß1-40/42 around vessels in AD brains. E. coli DNA or the E. coli K99 pili protein were detected in 9/10 control and 13/13 AD brains. Conclusions: LPS and E. coli bacterial proteins and DNA are found in control and AD brains. LPS co-localization with Aß1-40/42 in amyloid plaques and around vessels in AD brain suggest that LPS and/or other bacterial components could play a role in AD pathogenesis.
P2-285
CENTILOID THRESHOLDS FOR AMYLOID POSITIVITY DERIVED FROM AUTOPSY-PROVEN CASES
Nagehan Ayakta1,2, William W. Seeley3, Lea T. Grinberg3, Samuel N. Lockhart4, James P. O’Neil5, Rik Ossenkoppele2, Bruce Reed6, John Olichney7, Adam L. Boxer2, Bruce Miller2, Ewa Borys8, LeeWay Jin7, Eric Huang2, Charles DeCarli9, William J. Jagust4,10, Gil D. Rabinovici2, 1Helen Wills Neuroscience Institute, Berkeley, CA, USA; 2 University of California San Francisco, San Francisco, CA, USA; 3 University of California, San Francisco, San Francisco, CA, USA; 4 University of California Berkeley, Berkeley, CA, USA; 5Lawrence Berkeley National Laboratory, Berkeley, CA, USA; 6University of California Davis Alzheimer’s Center, Davis, CA, USA; 7UC Davis, Davis, CA, USA; 8Stritch School of Medicine, Loyola University, Chicago, IL, USA; 9University of California Davis, Davis, CA, USA; 10Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA. Contact e-mail: Nagehan. [email protected]
Background: Establishing thresholds for early detection of amyloid accumulation by PET has important implications for observational research and early interventional trials. However, currently used thresholds are dependent on lab-specific pre-processing and analytic approaches. The Centiloid method has been recently proposed for standardization of amyloid PET quantification across labs and tracers. In this project, we sought to establish Centiloid thresholds for amyloid positivity by examining patients studied with [11C]PiB-PET and autopsy. Methods: We first validated methodology by processing the core Centiloid image dataset available at GAAIN.org. The regression between UCSF/Berkeley and Pittsburgh-derived Centiloids yielded R2 ¼ 0.99943. Our autopsy cohort consisted of 60 subjects, most of whom had dementia at the time of death and who showed a wide range of amyloid accumulation at autopsy (Table 1). Their PiB-PET scans were processed with the Centiloid method and our internal pipeline (50-70 minute SUVRs, gray-cerebellum reference) to generate Centiloids. The relationship between Centiloids versus CERAD and Thal stages was investigated. Finally, we assessed the performance of two a priori thresholds previously introduced by our group (liberal –SUVR 1.21 ¼ 7.47 Centiloids; conservative –SUVR 1.40 ¼ 27.48 Centiloids), and further derived an empirical threshold by performing ROC analysis of the current dataset, using CERAD moderate-frequent plaques as the standard of truth. Results: CERAD none-sparse patients had a mean of -4.8566.88 Centiloids; the moderate-frequent group had 66.02650.45 Centiloids (t-test, p <0.001). The ROC analysis identified 9.50 Centiloids as the optimal threshold with 0.89
Figure 2. Distribution of Centiloids across Thai phases and CERAD scores. Thresholds 7.47 and 9.50 create a distinct divide between Thai phases 0-2 and 3-5 and identifies a majority of frequent CERAD as positive.
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Poster Presentations: Monday, July 25, 2016
Table 1 Summary of the autopsy cohort organized by the primary diagnosis at autopsy. AD, Alzheimer’s Disease, includes both AD and AD+DLB at autopsy, FTLD, Frontotemporal Lobar Degeneration, includes PSP, CBD. Pick’s Disease, and TDP-43, Mixed includes autopsy cases with 2 primary diagnoses. Other, includes prion disease and argyrophillic grain disease.
N Gender (M/F) Education Age at PET Tautopsy - TPET (years) Avg SUVR (STD) Avg Centiloid Avg Thal phase Avg Braak phase MMSE at PET CDR at PET ApoE E4 positive C90RF72
Total
AD
FTLD
Vascular
Mixed
Other
60 37/23 15.7 (2.8) 67.8 (9.6) 3.2 (2.0) 1.3 (0.5) 28.5 (50.4) 2.2 (1.9) 2.9 (2.3) 21.4 (7.2) 1.09 (0.8) 16 2
14 11/3 17.5 (2.5) 69.4 (116) 3.9 (1.8) 2 (0.5) 91.6 (46.7) 4.9 (0.4) 5.9 (0.3) 19.4 (6.0) 1.1 (0.5) 7 0
30 18/12 15.7 (2.6) 65.2 (6.7) 2.9 (1.9) 0.97 (0.13) -5.6 (15.2) 1.0 (1.06) 1.2 (1.2) 21.4 (8.2) 1.2 (0.88) 5 1
6 4/2 14 (2.5) 81.2 (5.0) 2.4 (1.5) 1.2 (0.29) 13.8 (27) 1.0 1.8 (0.7) 25.0 (6.4) 0.38 (0.5) 0 0
8 2/6 14.5 (2.8) 68.6 (4.5) 4.5 (2.8) 1.6 (0.45) 47.7 (51.9) 4.3 (0.95) 5.0 (0.93) 23 (6.2) 0.88 (0.92) 4 1
2 2/0 16.0 58.5 1.3 0.96 -4.6 n/a 2.0 26.0 0.75 0 0
sensitivity (95% CI:0.71-0.97), 1.00 specificity (0.86 – 1.00); AUC 0.91 (0.808-1.000) (Figure1). The a priori liberal threshold had identical sensitivity and specificity as the ROC-derived threshold. These thresholds also distinguished between Thal phases 0-2 and 3-5 (Figure2). The a prioriconservative threshold had sensitivity of 0.68 (0.48-0.83) and specificity of 1.00 (0.861.0). Conclusions: The a priori liberal threshold (7.47 Centiloids) and the ROC-derived threshold (9.50 Centiloids) showed excellent sensitivity/specificity, and could be considered for detection of early amyloid signal. By the time of AAIC we anticipate processing at least 100 additional cases currently being provided by multiple sites in order to validate these preliminary results. P2-286
pants with up to 7 years of follow-up and initial CSF protein concentrations available. Regional average GM density was calculated using SPM12 tissue segmentations (www.fil.ion.ucl. ac.uk/spm) for 78 regions covering all the brain’s gray matter (Klein and Tourville, 2012). A linear mixed model, including initial age, gender and diagnosis was independently calculated for each combination of brain regions and proteins available (N¼83). Statistical associations of the proteins with GM change over time were corrected for multiple comparisons (FDR; p<0.05). Results: High concentration of the T-Cell-Specific pro-
CSF INFLAMMATORY AND LIPID TRANSPORTER PROTEINS PREDICT GREY MATTER DENSITY LONGITUDINAL CHANGES
Melissa Savard1, Yasser Iturria Medina2, Cecile Madjar3, Ilana Leppert2, Anne Labonte3, Pedro Rosa-Neto4, Judes Poirier1, John C. S. Breitner5, PREVENT-AD Research Group, 1Centre for Studies on Prevention of Alzheimer’s Disease (StoP-AD Centre), Douglas Hospital Research Centre, Montreal, QC, Canada; 2McConnell Brain Imaging Center, Montreal Neurological Institute, Montreal, QC, Canada; 3Centre for Studies on Prevention of Alzheimer’s Disease (StoP-AD Centre), Douglas Mental Health Institute, Montreal, QC, Canada; 4Centre for Studies on Prevention of Alzheimer’s Disease (StoP-AD Centre), Douglas Mental Health Institute, Verdun, QC, Canada; 5Centre for Studies on Prevention of Alzheimer’s Disease (StoP-AD Centre), Douglas Hospital Research Centre,, Montreal, QC, Canada. Contact e-mail: [email protected] Background: Accumulating evidence links inflammation and cholesterol homeostasis to the pathogenesis of Alzheimer’s disease (AD) (Heppner et al. 2015; Wan et al. 2015). Glial cells react to inflammation (e.g., reactive gliosis) and may thus induce grey matter (GM) alterations. Preliminary findings from the PREVENT-AD cohort show that some CSF inflammatory proteins may predict cross-sectional GM integrity (Figure 1). We therefore investigated whether initial concentrations of CSF inflammatory or other proteins predicted longitudinal GM change in different stages of AD. Methods: We analyzed data from 137 Alzheimer’s Disease Neuroimaging Initiative (ADNI) partici-
Figure 1. Cross-sectional CSF inflammatory biomarkers predict regional GM mean diffusivity (MD) in the PREVENT-AD cohort (N¼45) Significant regional effect of VEGF, MCP-1 and IL-10 (age adjusted, FDR corrected) are shown in red for increased MD and in blue for reduced MD. Reduced mean diffusivity is consistent with restriction of water movement due to gliosis.
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hippocampus in 24-month-old rats than in that 12-month-old rats in mild stress. These data are characterised by increase number of hyperchromatic neurons and increase of iNOS and eNOS expression in perikaria of pyramidal neurons, at the same time it was found reducing eNOS expression in microvascular endothelium. These changes are accompanied by more severe cognitive disorders in 24-month-old rats which may accelerate the process of aging. *This investigation was supported by grant of Volgograd State Medical University. P2-284
LIPOPOLYSACCHARIDE AND E. COLI PROTEINS AND DNA IN ALZHEIMER’S DISEASE BRAINS COMPARED TO CONTROLS
Xinhua Zhan1, Boryana Stamova1, Lee-Way Jin2, Charles DeCarli3, Brett Phinney4, Frank R. Sharp1, 1University of California Davis, Sacramento, CA, USA; 2UC Davis, Davis, CA, USA; 3University of California Davis, Davis, CA, USA; 4University of California at Davis, Davis, CA, USA. Contact e-mail: [email protected] Background: Amyloid plaques in Alzheimer’s disease (AD) are believed to be derived in part from clevage products of amyloid precursor protein (APP). However, Gram-negative Escherichia coli (E. coli) bacteria and other microorganisms can form extracellular amyloid. Moreover, administration of Gram-negative bacterial derived Lipopolysaccharide (LPS) followed by ischemia and hypoxia produce plaque-like aggregates of myelin and amyloid ß in adult rat brains. These findings led us to examine human brain for LPS and E. coli proteins and DNA. Methods: Brain samples from superior temporal gyrus gray matter and frontal lobe white matter were studied from AD patients (n¼24) and age-matched controls (n¼18). LPS and E. coli proteins including K99 pili protein were evaluated by Western blots and immunocytochemistry. DNA from human brains was assessed for E. coli DNA. Results: LPS and E. coli K99 were detected immunocytochemically in brain parenchyma and vessels in all AD and control brains. K99 levels by Western blots were greater in AD compared to control brains (p < 0.01) and K99 was localized to neurons in AD but not control brains. LPS co-localized with Aß1-40/42 in amyloid plaques and with Aß1-40/42 around vessels in AD brains. E. coli DNA or the E. coli K99 pili protein were detected in 9/10 control and 13/13 AD brains. Conclusions: LPS and E. coli bacterial proteins and DNA are found in control and AD brains. LPS co-localization with Aß1-40/42 in amyloid plaques and around vessels in AD brain suggest that LPS and/or other bacterial components could play a role in AD pathogenesis.
P2-285
CENTILOID THRESHOLDS FOR AMYLOID POSITIVITY DERIVED FROM AUTOPSY-PROVEN CASES
Nagehan Ayakta1,2, William W. Seeley3, Lea T. Grinberg3, Samuel N. Lockhart4, James P. O’Neil5, Rik Ossenkoppele2, Bruce Reed6, John Olichney7, Adam L. Boxer2, Bruce Miller2, Ewa Borys8, LeeWay Jin7, Eric Huang2, Charles DeCarli9, William J. Jagust4,10, Gil D. Rabinovici2, 1Helen Wills Neuroscience Institute, Berkeley, CA, USA; 2 University of California San Francisco, San Francisco, CA, USA; 3 University of California, San Francisco, San Francisco, CA, USA; 4 University of California Berkeley, Berkeley, CA, USA; 5Lawrence Berkeley National Laboratory, Berkeley, CA, USA; 6University of California Davis Alzheimer’s Center, Davis, CA, USA; 7UC Davis, Davis, CA, USA; 8Stritch School of Medicine, Loyola University, Chicago, IL, USA; 9University of California Davis, Davis, CA, USA; 10Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA. Contact e-mail: Nagehan. [email protected]
Background: Establishing thresholds for early detection of amyloid accumulation by PET has important implications for observational research and early interventional trials. However, currently used thresholds are dependent on lab-specific pre-processing and analytic approaches. The Centiloid method has been recently proposed for standardization of amyloid PET quantification across labs and tracers. In this project, we sought to establish Centiloid thresholds for amyloid positivity by examining patients studied with [11C]PiB-PET and autopsy. Methods: We first validated methodology by processing the core Centiloid image dataset available at GAAIN.org. The regression between UCSF/Berkeley and Pittsburgh-derived Centiloids yielded R2 ¼ 0.99943. Our autopsy cohort consisted of 60 subjects, most of whom had dementia at the time of death and who showed a wide range of amyloid accumulation at autopsy (Table 1). Their PiB-PET scans were processed with the Centiloid method and our internal pipeline (50-70 minute SUVRs, gray-cerebellum reference) to generate Centiloids. The relationship between Centiloids versus CERAD and Thal stages was investigated. Finally, we assessed the performance of two a priori thresholds previously introduced by our group (liberal –SUVR 1.21 ¼ 7.47 Centiloids; conservative –SUVR 1.40 ¼ 27.48 Centiloids), and further derived an empirical threshold by performing ROC analysis of the current dataset, using CERAD moderate-frequent plaques as the standard of truth. Results: CERAD none-sparse patients had a mean of -4.8566.88 Centiloids; the moderate-frequent group had 66.02650.45 Centiloids (t-test, p <0.001). The ROC analysis identified 9.50 Centiloids as the optimal threshold with 0.89
Figure 2. Distribution of Centiloids across Thai phases and CERAD scores. Thresholds 7.47 and 9.50 create a distinct divide between Thai phases 0-2 and 3-5 and identifies a majority of frequent CERAD as positive.
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Poster Presentations: Monday, July 25, 2016
Table 1 Summary of the autopsy cohort organized by the primary diagnosis at autopsy. AD, Alzheimer’s Disease, includes both AD and AD+DLB at autopsy, FTLD, Frontotemporal Lobar Degeneration, includes PSP, CBD. Pick’s Disease, and TDP-43, Mixed includes autopsy cases with 2 primary diagnoses. Other, includes prion disease and argyrophillic grain disease.
N Gender (M/F) Education Age at PET Tautopsy - TPET (years) Avg SUVR (STD) Avg Centiloid Avg Thal phase Avg Braak phase MMSE at PET CDR at PET ApoE E4 positive C90RF72
Total
AD
FTLD
Vascular
Mixed
Other
60 37/23 15.7 (2.8) 67.8 (9.6) 3.2 (2.0) 1.3 (0.5) 28.5 (50.4) 2.2 (1.9) 2.9 (2.3) 21.4 (7.2) 1.09 (0.8) 16 2
14 11/3 17.5 (2.5) 69.4 (116) 3.9 (1.8) 2 (0.5) 91.6 (46.7) 4.9 (0.4) 5.9 (0.3) 19.4 (6.0) 1.1 (0.5) 7 0
30 18/12 15.7 (2.6) 65.2 (6.7) 2.9 (1.9) 0.97 (0.13) -5.6 (15.2) 1.0 (1.06) 1.2 (1.2) 21.4 (8.2) 1.2 (0.88) 5 1
6 4/2 14 (2.5) 81.2 (5.0) 2.4 (1.5) 1.2 (0.29) 13.8 (27) 1.0 1.8 (0.7) 25.0 (6.4) 0.38 (0.5) 0 0
8 2/6 14.5 (2.8) 68.6 (4.5) 4.5 (2.8) 1.6 (0.45) 47.7 (51.9) 4.3 (0.95) 5.0 (0.93) 23 (6.2) 0.88 (0.92) 4 1
2 2/0 16.0 58.5 1.3 0.96 -4.6 n/a 2.0 26.0 0.75 0 0
sensitivity (95% CI:0.71-0.97), 1.00 specificity (0.86 – 1.00); AUC 0.91 (0.808-1.000) (Figure1). The a priori liberal threshold had identical sensitivity and specificity as the ROC-derived threshold. These thresholds also distinguished between Thal phases 0-2 and 3-5 (Figure2). The a prioriconservative threshold had sensitivity of 0.68 (0.48-0.83) and specificity of 1.00 (0.861.0). Conclusions: The a priori liberal threshold (7.47 Centiloids) and the ROC-derived threshold (9.50 Centiloids) showed excellent sensitivity/specificity, and could be considered for detection of early amyloid signal. By the time of AAIC we anticipate processing at least 100 additional cases currently being provided by multiple sites in order to validate these preliminary results. P2-286
pants with up to 7 years of follow-up and initial CSF protein concentrations available. Regional average GM density was calculated using SPM12 tissue segmentations (www.fil.ion.ucl. ac.uk/spm) for 78 regions covering all the brain’s gray matter (Klein and Tourville, 2012). A linear mixed model, including initial age, gender and diagnosis was independently calculated for each combination of brain regions and proteins available (N¼83). Statistical associations of the proteins with GM change over time were corrected for multiple comparisons (FDR; p<0.05). Results: High concentration of the T-Cell-Specific pro-
CSF INFLAMMATORY AND LIPID TRANSPORTER PROTEINS PREDICT GREY MATTER DENSITY LONGITUDINAL CHANGES
Melissa Savard1, Yasser Iturria Medina2, Cecile Madjar3, Ilana Leppert2, Anne Labonte3, Pedro Rosa-Neto4, Judes Poirier1, John C. S. Breitner5, PREVENT-AD Research Group, 1Centre for Studies on Prevention of Alzheimer’s Disease (StoP-AD Centre), Douglas Hospital Research Centre, Montreal, QC, Canada; 2McConnell Brain Imaging Center, Montreal Neurological Institute, Montreal, QC, Canada; 3Centre for Studies on Prevention of Alzheimer’s Disease (StoP-AD Centre), Douglas Mental Health Institute, Montreal, QC, Canada; 4Centre for Studies on Prevention of Alzheimer’s Disease (StoP-AD Centre), Douglas Mental Health Institute, Verdun, QC, Canada; 5Centre for Studies on Prevention of Alzheimer’s Disease (StoP-AD Centre), Douglas Hospital Research Centre,, Montreal, QC, Canada. Contact e-mail: [email protected] Background: Accumulating evidence links inflammation and cholesterol homeostasis to the pathogenesis of Alzheimer’s disease (AD) (Heppner et al. 2015; Wan et al. 2015). Glial cells react to inflammation (e.g., reactive gliosis) and may thus induce grey matter (GM) alterations. Preliminary findings from the PREVENT-AD cohort show that some CSF inflammatory proteins may predict cross-sectional GM integrity (Figure 1). We therefore investigated whether initial concentrations of CSF inflammatory or other proteins predicted longitudinal GM change in different stages of AD. Methods: We analyzed data from 137 Alzheimer’s Disease Neuroimaging Initiative (ADNI) partici-
Figure 1. Cross-sectional CSF inflammatory biomarkers predict regional GM mean diffusivity (MD) in the PREVENT-AD cohort (N¼45) Significant regional effect of VEGF, MCP-1 and IL-10 (age adjusted, FDR corrected) are shown in red for increased MD and in blue for reduced MD. Reduced mean diffusivity is consistent with restriction of water movement due to gliosis.