Klafki, Hans-Wolfgang

[["dc.bibliographiccitation.firstpage","691"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Journal of Alzheimer's Disease"],["dc.bibliographiccitation.lastpage","705"],["dc.bibliographiccitation.volume","54"],["dc.contributor.author","Klafki, Hans-Wolfgang"],["dc.contributor.author","Hafermann, Henning"],["dc.contributor.author","Bauer, Chris"],["dc.contributor.author","Haußmann, Ute"],["dc.contributor.author","Kraus, Inga"],["dc.contributor.author","Schuchhardt, Johannes"],["dc.contributor.author","Muck, Stephan"],["dc.contributor.author","Scherbaum, Norbert"],["dc.contributor.author","Wiltfang, Jens"],["dc.date.accessioned","2017-09-07T11:44:28Z"],["dc.date.available","2017-09-07T11:44:28Z"],["dc.date.issued","2016"],["dc.description.abstract","A comprehensive assay validation campaign of a commercially available chemiluminescence multiplex immunoassay for the simultaneous measurement of the amyloid-β peptides Aβ38, Aβ40, and Aβ42 in human cerebrospinal fluid (CSF) is presented. The assay quality parameters we addressed included impact of sample dilution, parallelism, lower limits of detection, lower limits of quantification, intra- and inter-assay repeatability, analytical spike recoveries, and between laboratory reproducibility of the measurements. The assay performed well in our hands and fulfilled a number of predefined acceptance criteria. The CSF levels of Aβ40 and Aβ42 determined in a clinical cohort (n = 203) were statistically significantly correlated with available ELISA data of Aβ1–40 (n = 158) and Aβ1–42 (n = 179) from a different laboratory. However, Bland-Altman method comparison indicated systematic differences between the assays. The data presented here furthermore indicate that the CSF concentration of Aβ40 can surrogate total CSF Aβ and support the hypothesis that the Aβ42/Aβ40 ratio outperforms CSF Aβ42 alone as a biomarker for Alzheimer’s disease due to a normalization to total Aβ levels."],["dc.identifier.doi","10.3233/jad-160398"],["dc.identifier.gro","3151666"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8483"],["dc.language.iso","en"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.relation.issn","1387-2877"],["dc.title","Validation of a Commercial Chemiluminescence Immunoassay for the Simultaneous Measurement of Three Different Amyloid-β Peptides in Human Cerebrospinal Fluid and Application to a Clinical Cohort"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","121"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Alzheimer's Research & Therapy"],["dc.bibliographiccitation.volume","10"],["dc.contributor.author","Shahpasand-Kroner, Hedieh"],["dc.contributor.author","Klafki, Hans-W."],["dc.contributor.author","Bauer, Chris"],["dc.contributor.author","Schuchhardt, Johannes"],["dc.contributor.author","Hüttenrauch, Melanie"],["dc.contributor.author","Stazi, Martina"],["dc.contributor.author","Bouter, Caroline"],["dc.contributor.author","Wirths, Oliver"],["dc.contributor.author","Vogelgsang, Jonathan"],["dc.contributor.author","Wiltfang, Jens"],["dc.date.accessioned","2019-07-09T11:49:37Z"],["dc.date.available","2019-07-09T11:49:37Z"],["dc.date.issued","2018"],["dc.description.abstract","Abstract Background The quantification of amyloid-beta (Aβ) peptides in blood plasma as potential biomarkers of Alzheimer’s disease (AD) is hampered by very low Aβ concentrations and the presence of matrix components that may interfere with the measurements. Methods We developed a two-step immunoassay for the simultaneous measurement of the relative levels of Aβ38, Aβ40 and Aβ42 in human EDTA plasma. The assay was employed for the study of 23 patients with dementia of the Alzheimer’s type (AD-D) and 17 patients with dementia due to other reasons (OD). We examined relationships with the clinical diagnosis, cerebral Aβ load as quantified by amyloid-positron emission tomography, apolipoprotein E genotype, Aβ levels and Tau protein in cerebrospinal fluid. Results Preconcentration of plasma Aβ peptides by immunoprecipitation substantially facilitated their immunological measurements. The Aβ42/Aβ40 and Aβ42/Aβ38 ratios were statistically significantly lower in the AD-D patients than in the OD group. The areas under the receiver operating characteristic curves reached 0.87 for the Aβ42/Aβ40 ratio and 0.80 for the Aβ42/Aβ38 ratio. Conclusions The measurement of plasma Aβ peptides with an immunological assay can be improved by preconcentration via immunoprecipitation with an antibody against the Aβ amino-terminus and elution of the captured peptides by heating in a mild detergent-containing buffer. Our findings support the Aβ42/Aβ40 ratio in blood plasma as a promising AD biomarker candidate which correlates significantly with the validated core biomarkers of AD. Further studies will be needed for technical advancement of the assay and validation of the biomarker findings."],["dc.identifier.doi","10.1186/s13195-018-0448-x"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15726"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59592"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.publisher","BioMed Central"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","A two-step immunoassay for the simultaneous assessment of Aβ38, Aβ40 and Aβ42 in human blood plasma supports the Aβ42/Aβ40 ratio as a promising biomarker candidate of Alzheimer’s disease"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","96"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Fluids and Barriers of the CNS"],["dc.bibliographiccitation.volume","19"],["dc.contributor.author","Klafki, Hans-Wolfgang"],["dc.contributor.author","Morgado, Barbara"],["dc.contributor.author","Wirths, Oliver"],["dc.contributor.author","Jahn, Olaf"],["dc.contributor.author","Bauer, Chris"],["dc.contributor.author","Esselmann, Hermann"],["dc.contributor.author","Schuchhardt, Johannes"],["dc.contributor.author","Wiltfang, Jens"],["dc.date.accessioned","2022-12-05T09:15:24Z"],["dc.date.available","2022-12-05T09:15:24Z"],["dc.date.issued","2022-12-03"],["dc.date.updated","2022-12-04T04:11:01Z"],["dc.description.abstract","Abstract\r\n \r\n Background\r\n A reduced amyloid-β (Aβ)42/40 peptide ratio in blood plasma represents a peripheral biomarker of the cerebral amyloid pathology observed in Alzheimer’s disease brains. The magnitude of the measurable effect in plasma is smaller than in cerebrospinal fluid, presumably due to dilution by Aβ peptides originating from peripheral sources. We hypothesized that the observable effect in plasma can be accentuated to some extent by specifically measuring Aβ1–42 and Aβ1–40 instead of AβX–42 and AβX–40.\r\n \r\n \r\n Methods\r\n We assessed the plasma AβX–42/X–40 and Aβ1–42/1–40 ratios in an idealized clinical sample by semi-automated Aβ immunoprecipitation followed by closely related sandwich immunoassays. The amyloid-positive and amyloid-negative groups (dichotomized according to Aβ42/40 in cerebrospinal fluid) were compared regarding the median difference, mean difference, standardized effect size (Cohen’s d) and receiver operating characteristic curves. For statistical evaluation, we applied bootstrapping.\r\n \r\n \r\n Results\r\n The median Aβ1–42/1–40 ratio was 20.86% lower in amyloid-positive subjects than in the amyloid-negative group, while the median AβX–42/X–40 ratio was only 15.56% lower. The relative mean difference between amyloid-positive and amyloid-negative subjects was −18.34% for plasma Aβ1–42/1–40 compared to −15.50% for AβX–42/X–40. Cohen’s d was 1.73 for Aβ1–42/1–40 and 1.48 for plasma AβX–42/X–40. Unadjusted p-values < 0.05 were obtained after .632 bootstrapping for all three parameters. Receiver operating characteristic analysis indicated very similar areas under the curves for plasma Aβ1–42/1–40 and AβX–42/X–40.\r\n \r\n \r\n Conclusions\r\n Our findings support the hypothesis that the relatively small difference in the plasma Aβ42/40 ratio between subjects with and without evidence of brain amyloidosis can be accentuated by specifically measuring Aβ1–42/1–40 instead of AβX–42/X–40. A simplified theoretical model explaining this observation is presented."],["dc.identifier.citation","Fluids and Barriers of the CNS. 2022 Dec 03;19(1):96"],["dc.identifier.doi","10.1186/s12987-022-00390-4"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/118429"],["dc.language.iso","en"],["dc.rights","CC BY 4.0"],["dc.rights.holder","The Author(s)"],["dc.subject","Alzheimer’s disease"],["dc.subject","Biomarker"],["dc.subject","Amyloid-β peptides"],["dc.subject","Blood plasma"],["dc.subject","Aβ42/40 ratio"],["dc.subject","Immunoassay"],["dc.title","Is plasma amyloid-β 1–42/1–40 a better biomarker for Alzheimer’s disease than AβX–42/X–40?"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","127"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Alzheimer's Research & Therapy"],["dc.bibliographiccitation.volume","14"],["dc.contributor.author","Klafki, Hans-W."],["dc.contributor.author","Vogelgsang, Jonathan"],["dc.contributor.author","Manuilova, Ekaterina"],["dc.contributor.author","Bauer, Chris"],["dc.contributor.author","Jethwa, Alexander"],["dc.contributor.author","Esselmann, Hermann"],["dc.contributor.author","Jahn-Brodmann, Anke"],["dc.contributor.author","Osterloh, Dirk"],["dc.contributor.author","Lachmann, Ingolf"],["dc.contributor.author","Breitling, Benedict"],["dc.contributor.author","Rauter, Carolin"],["dc.contributor.author","Hansen, Niels"],["dc.contributor.author","Bouter, Caroline"],["dc.contributor.author","Palme, Stefan"],["dc.contributor.author","Schuchhardt, Johannes"],["dc.contributor.author","Wiltfang, Jens"],["dc.date.accessioned","2022-09-12T07:56:44Z"],["dc.date.available","2022-09-12T07:56:44Z"],["dc.date.issued","2022-09-07"],["dc.date.updated","2022-09-11T03:10:27Z"],["dc.description.abstract","Abstract\r\n \r\n Background\r\n Measurements of the amyloid-β (Aβ) 42/40 ratio in blood plasma may support the early diagnosis of Alzheimer’s disease and aid in the selection of suitable participants in clinical trials. Here, we compared the diagnostic performance of fully automated prototype plasma Aβ42/40 assays with and without pre-analytical sample workup by immunoprecipitation.\r\n \r\n \r\n Methods\r\n A pre-selected clinical sample comprising 42 subjects with normal and 38 subjects with low cerebrospinal fluid (CSF) Aβ42/40 ratios was studied. The plasma Aβ42/40 ratios were determined with fully automated prototype Elecsys® immunoassays (Roche Diagnostics GmbH, Penzberg, Germany) by direct measurements in EDTA plasma or after pre-analytical Aβ immunoprecipitation. The diagnostic performance for the detection of abnormal CSF Aβ42/40 was analyzed by receiver operating characteristic (ROC) analysis. In an additional post hoc analysis, a biomarker-supported clinical diagnosis was used as a second endpoint.\r\n \r\n \r\n Results\r\n Pre-analytical immunoprecipitation resulted in a significant increase in the area under the ROC curve (AUC) from 0.73 to 0.88 (p = 0.01547) for identifying subjects with abnormal CSF Aβ42/40. A similar improvement in the diagnostic performance by pre-analytical immunoprecipitation was also observed when a biomarker-supported clinical diagnosis was used as a second endpoint (AUC increase from 0.77 to 0.92, p = 0.01576).\r\n \r\n \r\n Conclusions\r\n Our preliminary observations indicate that pre-analytical Aβ immunoprecipitation can improve the diagnostic performance of plasma Aβ assays for detecting brain amyloid pathology. The findings may aid in the further development of blood-based immunoassays for Alzheimer’s disease ultimately suitable for screening and routine use."],["dc.identifier.citation","Alzheimer's Research & Therapy. 2022 Sep 07;14(1):127"],["dc.identifier.doi","10.1186/s13195-022-01071-y"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/114202"],["dc.language.iso","en"],["dc.rights","CC BY 4.0"],["dc.rights.holder","The Author(s)"],["dc.subject","Alzheimer’s disease"],["dc.subject","Biomarker assay"],["dc.subject","Plasma Amyloid-β 42/40"],["dc.subject","Immunoprecipitation"],["dc.subject","Pre-analytical sample workup"],["dc.title","Diagnostic performance of automated plasma amyloid-β assays combined with pre-analytical immunoprecipitation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]