Wiltfang, Jens

[["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"]]