Cerebrospinal fluid A beta 1-40 peptides increase in Alzheimer’s disease and are highly correlated with phospho-tau in control individuals
Bibliographic record
Abstract
ABSTRACT Background: Amyloid pathology, which is one of the characteristics of Alzheimer’s disease (AD), results from altered metabolism of the beta-amyloid peptide (Aβ) in terms of synthesis, clearance or aggregation. A decrease in cerebrospinal fluid (CSF) level Aβ 1-42 is evident in AD, and the CSF ratio Aβ 40 /Aβ 40 has recently been identified as one of the most reliable diagnostic biomarkers of amyloid pathology. Variations in inter-individual levels of Aβ 1-40 in the CSF have been observed in the past, but their origins remain unclear. In addition, the variation of Aβ 40 in the context of AD studied in several studies has yielded conflicting results. Methods Here, we analyzed the levels of Aβ 1-40 using multicenter data obtained on 2466 samples from six different cohorts in which CSF was collected under standardized protocols, centrifugation and storage conditions. Tau and p-tau(181) concentrations were measured using commercially available in vitro diagnostic immunoassays. Concentrations of CSF Aβ 1-42 and Aβ 1-40 were measured by ELISA, xMAP technology, chemiluminescence immunoassay (CLIA) and mass spectrometry. Statistical analyses were calculated for parametric and non-parametric comparisons, linear regression, correlation and odds ratios. The statistical tests were adjusted for the effects of covariates (age, in particular). Results: Regardless of the analysis method used and the cohorts, a slight but significant age-independent increase in the levels of Aβ 40 in CSF was observed in AD. We also found a strong positive correlation between the levels of Aβ 40 and p-tau(181) in CSF, particularly in control patients. Conclusions: These results indicate that an increase in the baseline level of amyloid peptides, which are associated with an increase in p-tau(181), may be a biological characteristic of AD. This confirms the potential therapeutic value of lowering the baseline levels of Aβ 40 which, being elevated, can be considered a risk factor for the disease.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".