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Analytical performance of a delayed-centrifugation blood collection tube for remote blood biomarker assessment
Lee Y, Zeng X, Farinas MF, Lopresti BJ, Habte RF, Wilckens KA, Karikari TK.. medRxiv, 2026-10-07
Topic: Plasma and spinal-fluid biomarkers
Current biobanking guidelines require in-person blood collection and immediate processing for Alzheimer’s disease (AD) biomarker assessment. We recently reported that the P100 blood collection tubes containing protease inhibitors improve protein biomarker stability over delayed centrifugation periods. However, whether this comparability extends beyond a small set of biomarkers to the broad panels enabled by high-plex platforms has not been established. Here, we performed a head-to-head comparison of 127 neurodegeneration-related biomarkers in paired P100 vs. standard ethylenediaminetetraacetic acid (EDTA) plasma samples from n = 43 community-dwelling older adult participants using the NUcleic acid-Linked Immuno-Sandwich Assay (NULISA) proteomic technology. The NULISA assay demonstrated excellent technical reproducibility (intra- and inter-plate coefficients of variation [CVs] <10%). Biomarker levels in P100 and EDTA tubes were strongly correlated, with mean and median Spearman coefficients exceeding ρ = 0.8. Six conventional AD biomarkers showed strong P100–EDTA correlations (ρ > 0.8) with minimal mean differences and no significant proportional bias in Bland–Altman analysis, including plasma Aβ42, GFAP, MAPT, NEFL, p-tau181, and p-tau231, while p-tau217 showed a P100–EDTA correlation of ρ = 0.57. Two biomarker ratios (Aβ42/Aβ40 and p-tau217/Aβ42) also showed minimal bias with no proportional bias detected. Receiver operating characteristic analysis using amyloid status, assessed with positron emission tomography in a subset of participants, showed comparable classification performance between the two tube types, with classification concordance up to 92% and no significant DeLong differences for most (80%) biomarkers. These findings indicate that, on the NULISA platform, P100 tubes yield analytical and classification performance comparable to conventional EDTA tubes, supporting their use for blood-based neurodegeneration biomarker research where immediate sample processing is not feasible.
Key findings
- The NULISA assay demonstrated excellent technical reproducibility (intra- and inter-plate coefficients of variation [CVs] <10%).
- Six conventional AD biomarkers showed strong P100–EDTA correlations (ρ > 0.8) with minimal mean differences and no significant proportional bias in Bland–Altman analysis, including plasma Aβ42, GFAP, MAPT, NEFL, p-tau181, and p-tau231, while p-tau217 showed a P100–EDTA correlation of ρ = 0.57.
- Receiver operating characteristic analysis using amyloid status, assessed with positron emission tomography in a subset of participants, showed comparable classification performance between the two tube types, with classification concordance up to 92% and no significant DeLong differences for most (80%) biomarkers.
- These findings indicate that, on the NULISA platform, P100 tubes yield analytical and classification performance comparable to conventional EDTA tubes, supporting their use for blood-based neurodegeneration biomarker research where immediate sample processing is not feasible.
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Study details
- Participants43
- Evidence strengthLow
How this study scored 16/100
Preprint — not yet peer-reviewed. It scored 27 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 17 of the 62 points we could judge it on, which is 27 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 | 1 / 4 | 43 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 | 17 / 62 | Scored on 12 of 20 parts. We have no data for the rest, so they are left out: 17 of the 62 points we could judge it on is 27 out of 100. |
| Total | 27 / 100 | Capped to 16 because this is not a peer-reviewed article. |
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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 names 7 authors; APA and Vancouver show the first six, BibTeX and the downloads carry all of them. Check the citation against the original before you use it.
APA 7th
Lee, Y., Zeng, X., Farinas, M. F., Lopresti, B. J., Habte, R. F., Wilckens, K. A., et al. (2026). Analytical performance of a delayed-centrifugation blood collection tube for remote blood biomarker assessment. medRxiv. https://doi.org/10.64898/2026.10.05.26364780
Vancouver
Lee Y, Zeng X, Farinas MF, Lopresti BJ, Habte RF, Wilckens KA, et al. Analytical performance of a delayed-centrifugation blood collection tube for remote blood biomarker assessment. medRxiv. 2026. doi:10.64898/2026.10.05.26364780.
BibTeX
@article{lee2026-4cc33be6,
author = {Lee, Y. and Zeng, X. and Farinas, M. F. and Lopresti, B. J. and Habte, R. F. and Wilckens, K. A. and Karikari, T. K.},
title = {{Analytical performance of a delayed-centrifugation blood collection tube for remote blood biomarker assessment}},
journal = {medRxiv},
year = {2026},
doi = {10.64898/2026.10.05.26364780},
url = {https://doi.org/10.64898/2026.10.05.26364780}
}