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Longitudinal Evaluation of 18 F-MK-6240 Along the Alzheimer Disease Continuum
Anna O. Giarratana, Erin McMullen Jonaitis, Robert J. Przybelski, Karly Alex Cody, Tobey J. Betthauser, Robert V. Cadman, Sara Frost Alberson, Bradley T. Christian et al.. Journal of Nuclear Medicine, 2026-04-02
Topic: Amyloid, tau and blood-test diagnosis
Baseline 18F-MK-6240 PET showed a minimal signal in CU participants, localized signal to the medial temporal lobe in participants with MCI, and a signal spanning the inferolateral temporal lobe and extending posteriorly along the ventral cortex in participants with AD. Longitudinal analysis showed that the annualized percent change in tau deposition in the MTC was 0.17% ± 4.16, 5.77% ± 2.97, and 4.31% ± 5.84 in the CU, MCI, and AD groups, respectively (P = 0.075). The change in tau deposition was 0.00 ± 0.05, 0.10 ± 0.07, and 0.12 ± 0.16 in the CU, MCI, and AD groups, respectively (P = 0.039). Tau accumulation correlated with a decline on the Alzheimer Disease Assessment Scale–Cognitive Subscale (ρ = 0.43, P < 0.05). Conclusion:18F-MK-6240 PET tracked tau accumulation over time and provided preliminary evidence that these changes correlate with cognitive decline, supporting its utility for longitudinal AD studies and trial design, with MTC emerging as a promising ROI for clinical trials.
Key findings
- Baseline 18F-MK-6240 PET showed a minimal signal in CU participants, localized signal to the medial temporal lobe in participants with MCI, and a signal spanning the inferolateral temporal lobe and extending posteriorly along the ventral cortex in participants with AD.
- Longitudinal analysis showed that the annualized percent change in tau deposition in the MTC was 0.17% ± 4.16, 5.77% ± 2.97, and 4.31% ± 5.84 in the CU, MCI, and AD groups, respectively (P = 0.075).
- The change in tau deposition was 0.00 ± 0.05, 0.10 ± 0.07, and 0.12 ± 0.16 in the CU, MCI, and AD groups, respectively (P = 0.039).
- Tau accumulation correlated with a decline on the Alzheimer Disease Assessment Scale–Cognitive Subscale (ρ = 0.43, P < 0.05).
- Conclusion:18F-MK-6240 PET tracked tau accumulation over time and provided preliminary evidence that these changes correlate with cognitive decline, supporting its utility for longitudinal AD studies and trial design, with MTC emerging as a promising ROI for clinical trials.
Why it matters
This study used a tau PET tracer to track tau buildup over time in people at different stages of Alzheimer's disease, and found that tau accumulation correlated with cognitive decline. It is a brain imaging study for monitoring disease progression and does not test any treatment, cure, or prevention.
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Study details
- Study designlongitudinal study
- Participants27
- Effect size0.17%; 5.77%; 4.31%
- Evidence strengthModerate
How this study scored 54/100
Published in a peer-reviewed journal, and it is a longitudinal study following the same people over time. Scored zero for randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Journal of Nuclear Medicine) |
| Journal's citation record | 2 / 4 | Journal of Nuclear Medicine: journal h-index 230 (OpenAlex, 2026-10-29) |
| Study design | 7 / 12 | A longitudinal study following the same people over time |
| 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 | 5 / 5 | 2026 — within 1 year(s) of the newest study here |
| Sample size | 1 / 4 | 27 participants |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| 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 | 1 / 7 | Cited 1 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.5 citations a year over 2 year(s) since 2026 |
| Impact for its field and year | 3 / 6 | Cited 4.7× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 0 / 4 | Cited 1 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Sterling C. Johnson: h-index 112 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University of Wisconsin–Madison: institution h-index 1,518 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 41927280) |
| Free to read | 2 / 2 | Free to read |
| Total | 54 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
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.
APA 7th
Giarratana, A. O., Jonaitis, E. M., Przybelski, R. J., Cody, K. A., Betthauser, T. J., Cadman, R. V., et al. (2026). Longitudinal Evaluation of 18 F-MK-6240 Along the Alzheimer Disease Continuum. Journal of Nuclear Medicine. https://doi.org/10.2967/jnumed.125.271127
Vancouver
Giarratana AO, Jonaitis EM, Przybelski RJ, Cody KA, Betthauser TJ, Cadman RV, et al. Longitudinal Evaluation of 18 F-MK-6240 Along the Alzheimer Disease Continuum. Journal of Nuclear Medicine. 2026. doi:10.2967/jnumed.125.271127. PMID: 41927280.
BibTeX
@article{giarratana2026-41927280,
author = {Giarratana, Anna O. and Jonaitis, Erin McMullen and Przybelski, Robert J. and Cody, Karly Alex and Betthauser, Tobey J. and Cadman, Robert V. and Alberson, Sara Frost and Christian, Bradley T. and others},
title = {{Longitudinal Evaluation of 18 F-MK-6240 Along the Alzheimer Disease Continuum}},
journal = {Journal of Nuclear Medicine},
year = {2026},
doi = {10.2967/jnumed.125.271127},
pmid = {41927280},
url = {https://doi.org/10.2967/jnumed.125.271127}
}
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