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Brain-Derived pTau217 and Plasma Proteomic Profiles Across Cognitive and Dementia Groups in Congolese Older Adults
Ikanga J, Patel SS, Boots T, Zeng X, Obenauf C, Gikelekele G, Epenge E, Potshi JM et al.. medRxiv, 2026-10-28
Topic: Genetics and APOE
Blood-based biomarkers for Alzheimer disease and related dementias have been validated largely in populations of European ancestry. We characterized plasma proteins in 786 adults aged 65 years or older in Kinshasa, Democratic Republic of the Congo, classified as cognitively unimpaired, mild cognitive impairment, suspected Alzheimer disease, mixed dementia, or vascular dementia. Proteins were quantified with the NULISAseq CNS Disease Panel 120. Sex showed the strongest associations with protein expression, followed by age, whereas APOE ε4 carrier status was associated with four measures. MME was downregulated across all dementia groups and showed the largest effect in each dementia-versus-CU comparison. A random forest model combining 10 biomarkers with age, sex, and APOE ε4 carrier status achieved a mean cross-validated area under the curve of 0.768, compared with 0.612 for brain-derived pTau217 alone. Because biomarker selection and ranking were performed using the full dataset before cross-validation, model performance may be optimistic. These findings support demographic adjustment and population-specific validation of plasma biomarkers and identify MME as a hypothesis-generating signal for further study.
Key findings
- Sex showed the strongest associations with protein expression, followed by age, whereas APOE ε4 carrier status was associated with four measures.
- MME was downregulated across all dementia groups and showed the largest effect in each dementia-versus-CU comparison.
- A random forest model combining 10 biomarkers with age, sex, and APOE ε4 carrier status achieved a mean cross-validated area under the curve of 0.768, compared with 0.612 for brain-derived pTau217 alone.
- These findings support demographic adjustment and population-specific validation of plasma biomarkers and identify MME as a hypothesis-generating signal for further study.
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Study details
- Participants786
- Evidence strengthLow
How this study scored 16/100
Preprint — not yet peer-reviewed. It scored 29 on the same rubric, but non-peer-reviewed sources are capped at 16, so it shows as 16. Scored zero for study design, effect reported and randomised / blinded because the record does not state it. We have no data on times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record, institution's track record and multi-centre collaboration, so those were left out: it earned 18 of the 62 points we could judge it on, which is 29 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 2 / 10 | Tier 4 — not a peer-reviewed journal (medRxiv) |
| Journal's citation record | 0 / 4 | Not a journal article, so the journal's record does not count |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 4 / 10 | Preprint — not yet peer-reviewed. Hosted on a preprint server. |
| How recent | 5 / 5 | 2026 — within 1 year(s) of the newest study here |
| Sample size | 2 / 4 | 786 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| 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 | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | — / 3 | Institutions not listed — left out of this score |
| Indexed in PubMed | 1 / 2 | Not in PubMed, but has a DOI |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 18 / 62 | Scored on 12 of 20 parts. We have no data for the rest, so they are left out: 18 of the 62 points we could judge it on is 29 out of 100. |
| Total | 29 / 100 | Capped to 16 because this is not a peer-reviewed article. |
What each of these 20 components measures, and what this score is not →
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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
Ikanga, J., Patel, S. S., Boots, T., Zeng, X., Obenauf, C., Gikelekele, G., et al. (2026). Brain-Derived pTau217 and Plasma Proteomic Profiles Across Cognitive and Dementia Groups in Congolese Older Adults. medRxiv. https://doi.org/10.64898/2026.10.26.26366533
Vancouver
Ikanga J, Patel SS, Boots T, Zeng X, Obenauf C, Gikelekele G, et al. Brain-Derived pTau217 and Plasma Proteomic Profiles Across Cognitive and Dementia Groups in Congolese Older Adults. medRxiv. 2026. doi:10.64898/2026.10.26.26366533.
BibTeX
@article{ikanga2026-b635ff16,
author = {Ikanga, J. and Patel, S. S. and Boots, T. and Zeng, X. and Obenauf, C. and Gikelekele, G. and Epenge, E. and Potshi, J. M. and others},
title = {{Brain-Derived pTau217 and Plasma Proteomic Profiles Across Cognitive and Dementia Groups in Congolese Older Adults}},
journal = {medRxiv},
year = {2026},
doi = {10.64898/2026.10.26.26366533},
url = {https://doi.org/10.64898/2026.10.26.26366533}
}
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