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Age-Specific Control and Alzheimer Disease Reference Curves and z -Scores for Glial Fibrillary Acidic Protein in Blood
Steffen Halbgebauer, Badrieh Fazeli, Veronika Klose, Gabriele Nagel, Angela Rosenbohm, Dietrich Rothenbacher, Franziska Bachhuber, Sarah Jesse et al.. Clinical Chemistry, 2025-09-19
Topic: Amyloid, tau and blood-test diagnosis
AD exhibited elevated serum GFAP levels in comparison to control patients (P < 0.0001). This remained the case when the newly generated age-corrected z-scores were applied (P < 0.0001). In the control cohort, a nonlinear elevation of serum GFAP with increasing age was observed (Spearman correlation coefficient 0.62, 95% CI 0.58-0.66, P < 0.0001). In contrast, the AD cohort exhibited a more linear increase (0.16, 95% CI 0.05-0.26, P = 0.004). Age-dependent cut-offs for serum GFAP were determined for different AD age groups. The calculated areas under the curve (AUCs; 0.97) demonstrated excellent diagnostic test performance in the early-onset age group. This effect was less marked in the elderly subjects (AUC 0.72). Our novel GFAP z-scores enable the integration and interpretation of serum GFAP levels in clinical practice, moving from the group to individual level. They support both intra- and interindividual interpretation of single GFAP levels in neurological diseases with astrocytic pathology, including an accurate discrimination of AD.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Halbgebauer, S., Fazeli, B., Klose, V., Nagel, G., Rosenbohm, A., Rothenbacher, D., et al. (2025). Age-Specific Control and Alzheimer Disease Reference Curves and z -Scores for Glial Fibrillary Acidic Protein in Blood. Clinical Chemistry. https://doi.org/10.1093/clinchem/hvaf120
Vancouver
Halbgebauer S, Fazeli B, Klose V, Nagel G, Rosenbohm A, Rothenbacher D, et al. Age-Specific Control and Alzheimer Disease Reference Curves and z -Scores for Glial Fibrillary Acidic Protein in Blood. Clinical Chemistry. 2025. doi:10.1093/clinchem/hvaf120. PMID: 41081630.
BibTeX
@article{halbgebauer2025-41081630,
author = {Halbgebauer, Steffen and Fazeli, Badrieh and Klose, Veronika and Nagel, Gabriele and Rosenbohm, Angela and Rothenbacher, Dietrich and Bachhuber, Franziska and Jesse, Sarah and others},
title = {{Age-Specific Control and Alzheimer Disease Reference Curves and z -Scores for Glial Fibrillary Acidic Protein in Blood}},
journal = {Clinical Chemistry},
year = {2025},
doi = {10.1093/clinchem/hvaf120},
pmid = {41081630},
url = {https://doi.org/10.1093/clinchem/hvaf120}
}
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
Key findings
- AD exhibited elevated serum GFAP levels in comparison to control patients (P < 0.0001).
- This remained the case when the newly generated age-corrected z-scores were applied (P < 0.0001).
- In the control cohort, a nonlinear elevation of serum GFAP with increasing age was observed (Spearman correlation coefficient 0.62, 95% CI 0.58-0.66, P < 0.0001).
- In contrast, the AD cohort exhibited a more linear increase (0.16, 95% CI 0.05-0.26, P = 0.004).
- Age-dependent cut-offs for serum GFAP were determined for different AD age groups.
Why it matters
Serum GFAP was elevated in Alzheimer's disease compared with controls, and age-corrected z-scores and cut-offs were developed, with better diagnostic performance in early-onset than elderly groups. This is a diagnostic tool and does not address treating, curing or preventing the disease.
New to this subject? Start with our plain-English guide: Blood tests & biomarkers →
Study details
- Participants1,273
- Effect sizeAUC 0.72
- Evidence strengthModerate
How this study scored 55/100
Published in a peer-reviewed journal. Scored zero for study design and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Clinical Chemistry) |
| Journal's citation record | 3 / 4 | Clinical Chemistry: journal h-index 323 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 4 / 5 | 2025 — within 3 year(s) of the newest study here |
| Sample size | 3 / 4 | 1,273 participants |
| Effect reported | 3 / 3 | Effect reported with a statistic (interval, p-value, ratio or similar) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 2 / 7 | Cited 9 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 3.0 citations a year over 3 year(s) since 2025 |
| Impact for its field and year | 3 / 6 | Cited 5.7× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 1 other studies in this library |
| Still being cited | 1 / 4 | Cited 9 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Hayrettin Tumani: h-index 41 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University of California, San Francisco: institution h-index 1,915 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 8 institution(s) in 3 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 41081630) |
| Free to read | 2 / 2 | Free to read |
| Total | 55 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.1093/clinchem/hvaf120
- PubMed: 41081630
- Original source →
- Free full text: Clinical Chemistry →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
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