- Email: [email protected]
DEVELOPMENT OF HIGHLY SENSITIVE MSD ASSAYS FOR THE DETECTION OF ANTI-AMYLOID β MONOMER- AND OLIGOMER-SPECIFIC ANTIBODIES IN HUMAN SERUM
Poster Presentations: Tuesday, July 18, 2017
specific filters on pipeline-unique variants. To analyze WGS of 578 family samples and WES of 10,692 case/control samples from the Alzheimer’s Disease Sequencing Project (ADSP), structured protocols were developed and implemented for post-variant calling QC and consensus calling, and will be implemented on multiple replication sequence datasets. Conclusions: The pipeline generates fully QCed/consensus called genotypes in multiple formats, as well as extensive annotation of variants and genotypes both passing and failing the QC/ consensus calling steps. The pipeline is currently in beta-testing, and pipeline design and results of the implementation of the pipeline on both ADSP Discovery and preliminary ADSP replication datasets will be presented.
P3-066
ELECTROPHYSIOLOGY DEPENDS ON SEX IN AGING AND DEMENTIA
on Snædal2, þorkell Elı Guðmundsson2, Magnus Johannsson1, J Gısli H olmar J ohannesson1, Kristinn Johnsen1, 1Mentis Cura, Reykjavik, Iceland; 2Landspitali University Hospital, Reykjavik, Iceland. Contact e-mail: [email protected] Background: Longitudinal studies on sex differences in cognitive decline have reported inconsistent findings where some studies show difference in decline while others not. Converging evidence suggest the role of large scale neurocognitive networks in memory and other cognitive functions of the brain. Acetycholine (Ach) serves as neuromodulator by altering the way neurocognitive networks respond to external and internal inputs. The aim of the present work was to investigate the behavior of a previously designed ACH index across progressive stages of dementia; and to investigate possible sex differences in cognitive aging in healthy individuals. Methods: The ACH activity, in terms of the index and possible role of sex in cognitive aging was examined using EEG recordings from a population ranging from 5 – 95 years including healthy controls (NRM) as well as mild cognitive impairment (MCI), mild and severe Alzheimer’s disease (mAD and ADs) and Lewy body dementia (LBD) (N¼1697). Results: A significant difference was found for the ACH index between all pair of groups [F (4) ¼ 23.8, p ¼ 0.001] apart from the mAD and the NRM group and the LBD and ADs group. A medium positive correlation (r¼ 0.31, p < 0.001) was found between the ACH index and cognition as measured with MMSE. Looking at sex differences a significant difference [F (1) ¼ 66.74, p ¼ 0.001] was found for the ACH index between females and males in the elderly (mean age ¼ 71.8 (sd.¼10.2)) and women showed a higher positive correlation to MMSE in the ADs and LBD groups compared to the men. Conclusions: In conclusion, this study introduces the ACH index, developed on the basis of a scopolamine challenge trial. The ACH index reflects progressive loss of cholinergic function ranging from normal cognition through MCI and mild AD to severe AD; it correlates with cognition and a clear sex difference was found related to cognitive aging. The results also imply that sex may play a crucial role in EEG related research and application in dementia.
P3-067
P957
DEVELOPMENT OF HIGHLY SENSITIVE MSD ASSAYS FOR THE DETECTION OF ANTI-AMYLOID b MONOMER- AND OLIGOMER-SPECIFIC ANTIBODIES IN HUMAN SERUM
Marija Vukicevic, Emma Fiorini, Delphine Knittel, Valerie Giriens, Nathalie Chuard, Andrea Pfeifer, Andreas Muhs, Maria Pihlgren, AC Immune SA, Lausanne, Switzerland. Contact e-mail: marija.vukicevic@ acimmune.com Background: In the field of Amyloid beta (Ab) immunotherapy, robust and reliable methods are needed for the detection of antibodies specific for different pathological Ab species. We have developed highly sensitive Meso Scale Discovery (MSD) assays for the detection of IgG antibodies specific for the monomeric or oligomeric Ab1-42 in human serum. Those assays aim to help better understanding of the nature of antibody response induced by anti-Ab vaccination. Methods: For the detection of Ab1-42-specific IgG (assay 1), MSD plates have been directly coated with the Ab1-42 peptide monomers. Monkey positive serum containing Ab1-42specific antibodies was incubated. The reaction was revealed with an anti-IgG antibody (recognizing monkeys and humans). This assay was compared to assay 2 using streptavidin plates coated with the biotinylated anti-Ab monoclonal antibody (6E10 or 12F4, specific for N- or C-terminus of Ab1-42, respectively), capturing oligomeric Ab1-42. Monkey serum containing Ab-oligomer-specific antibodies was incubated. The reaction was revealed with the anti-human IgG. Results: In the assay 1, matrix effect of na€ıve sera was reduced by saturating the plates in the BSA and diluting the samples in milk. The developed assay showed a very high sensitivity (at least eight times higher than ELISA), good precision and a very high dynamic range with serum minimal required dilution (MRD) of 1:50. In the assay 2, oligomer-specific IgG gave much higher signal with 6E10 than 12F4 antibody; this setup was further optimized. The assay showed a high sensitivity (at least three times higher than the ELISA using a direct coating of Ab oligomers) and a very high dynamic range. In addition, the assay gave a good precision without a matrix effect at MRD of 1:50. Both assays showed a good robustness, reproducibility in time and among different operators. Conclusions: We have optimized the MSD assays for the detection of different Ab-specific IgG, which were more sensitive than the ELISA assays. This suggested the suitability of the MSD technology for the evaluation of the quality of anti-Ab antibodies specific for different pathological Ab species, which could be further used for the evaluation of the potential therapeutic effect of anti-Ab immunotherapy in humans.
P3-068
DEVELOPMENT OF AN ULTRASENSITIVE DIGITAL IMMUNOASSAY FOR THE MEASUREMENT OF LRRK2 IN CEREBROSPINAL FLUID
Nathan Estochen1, Dipika Gemani1, Melissa Berman2, Linan Song1, David Hanlon1, Andreas Jeromin1, Danielle Graham2, 1Quanterix Corporation, Lexington, MA, USA; 2Biogen, Cambridge, MA, USA. Contact e-mail: [email protected]
specific filters on pipeline-unique variants. To analyze WGS of 578 family samples and WES of 10,692 case/control samples from the Alzheimer’s Disease Sequencing Project (ADSP), structured protocols were developed and implemented for post-variant calling QC and consensus calling, and will be implemented on multiple replication sequence datasets. Conclusions: The pipeline generates fully QCed/consensus called genotypes in multiple formats, as well as extensive annotation of variants and genotypes both passing and failing the QC/ consensus calling steps. The pipeline is currently in beta-testing, and pipeline design and results of the implementation of the pipeline on both ADSP Discovery and preliminary ADSP replication datasets will be presented.
P3-066
ELECTROPHYSIOLOGY DEPENDS ON SEX IN AGING AND DEMENTIA
on Snædal2, þorkell Elı Guðmundsson2, Magnus Johannsson1, J Gısli H olmar J ohannesson1, Kristinn Johnsen1, 1Mentis Cura, Reykjavik, Iceland; 2Landspitali University Hospital, Reykjavik, Iceland. Contact e-mail: [email protected] Background: Longitudinal studies on sex differences in cognitive decline have reported inconsistent findings where some studies show difference in decline while others not. Converging evidence suggest the role of large scale neurocognitive networks in memory and other cognitive functions of the brain. Acetycholine (Ach) serves as neuromodulator by altering the way neurocognitive networks respond to external and internal inputs. The aim of the present work was to investigate the behavior of a previously designed ACH index across progressive stages of dementia; and to investigate possible sex differences in cognitive aging in healthy individuals. Methods: The ACH activity, in terms of the index and possible role of sex in cognitive aging was examined using EEG recordings from a population ranging from 5 – 95 years including healthy controls (NRM) as well as mild cognitive impairment (MCI), mild and severe Alzheimer’s disease (mAD and ADs) and Lewy body dementia (LBD) (N¼1697). Results: A significant difference was found for the ACH index between all pair of groups [F (4) ¼ 23.8, p ¼ 0.001] apart from the mAD and the NRM group and the LBD and ADs group. A medium positive correlation (r¼ 0.31, p < 0.001) was found between the ACH index and cognition as measured with MMSE. Looking at sex differences a significant difference [F (1) ¼ 66.74, p ¼ 0.001] was found for the ACH index between females and males in the elderly (mean age ¼ 71.8 (sd.¼10.2)) and women showed a higher positive correlation to MMSE in the ADs and LBD groups compared to the men. Conclusions: In conclusion, this study introduces the ACH index, developed on the basis of a scopolamine challenge trial. The ACH index reflects progressive loss of cholinergic function ranging from normal cognition through MCI and mild AD to severe AD; it correlates with cognition and a clear sex difference was found related to cognitive aging. The results also imply that sex may play a crucial role in EEG related research and application in dementia.
P3-067
P957
DEVELOPMENT OF HIGHLY SENSITIVE MSD ASSAYS FOR THE DETECTION OF ANTI-AMYLOID b MONOMER- AND OLIGOMER-SPECIFIC ANTIBODIES IN HUMAN SERUM
Marija Vukicevic, Emma Fiorini, Delphine Knittel, Valerie Giriens, Nathalie Chuard, Andrea Pfeifer, Andreas Muhs, Maria Pihlgren, AC Immune SA, Lausanne, Switzerland. Contact e-mail: marija.vukicevic@ acimmune.com Background: In the field of Amyloid beta (Ab) immunotherapy, robust and reliable methods are needed for the detection of antibodies specific for different pathological Ab species. We have developed highly sensitive Meso Scale Discovery (MSD) assays for the detection of IgG antibodies specific for the monomeric or oligomeric Ab1-42 in human serum. Those assays aim to help better understanding of the nature of antibody response induced by anti-Ab vaccination. Methods: For the detection of Ab1-42-specific IgG (assay 1), MSD plates have been directly coated with the Ab1-42 peptide monomers. Monkey positive serum containing Ab1-42specific antibodies was incubated. The reaction was revealed with an anti-IgG antibody (recognizing monkeys and humans). This assay was compared to assay 2 using streptavidin plates coated with the biotinylated anti-Ab monoclonal antibody (6E10 or 12F4, specific for N- or C-terminus of Ab1-42, respectively), capturing oligomeric Ab1-42. Monkey serum containing Ab-oligomer-specific antibodies was incubated. The reaction was revealed with the anti-human IgG. Results: In the assay 1, matrix effect of na€ıve sera was reduced by saturating the plates in the BSA and diluting the samples in milk. The developed assay showed a very high sensitivity (at least eight times higher than ELISA), good precision and a very high dynamic range with serum minimal required dilution (MRD) of 1:50. In the assay 2, oligomer-specific IgG gave much higher signal with 6E10 than 12F4 antibody; this setup was further optimized. The assay showed a high sensitivity (at least three times higher than the ELISA using a direct coating of Ab oligomers) and a very high dynamic range. In addition, the assay gave a good precision without a matrix effect at MRD of 1:50. Both assays showed a good robustness, reproducibility in time and among different operators. Conclusions: We have optimized the MSD assays for the detection of different Ab-specific IgG, which were more sensitive than the ELISA assays. This suggested the suitability of the MSD technology for the evaluation of the quality of anti-Ab antibodies specific for different pathological Ab species, which could be further used for the evaluation of the potential therapeutic effect of anti-Ab immunotherapy in humans.
P3-068
DEVELOPMENT OF AN ULTRASENSITIVE DIGITAL IMMUNOASSAY FOR THE MEASUREMENT OF LRRK2 IN CEREBROSPINAL FLUID
Nathan Estochen1, Dipika Gemani1, Melissa Berman2, Linan Song1, David Hanlon1, Andreas Jeromin1, Danielle Graham2, 1Quanterix Corporation, Lexington, MA, USA; 2Biogen, Cambridge, MA, USA. Contact e-mail: [email protected]