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The PrecivityAD™ test: Accurate and reliable LC-MS/MS assays for quantifying plasma amyloid beta 40 and 42 and apolipoprotein E proteotype for the assessment of brain amyloidosis
Kirmess KM, Meyer MR, Holubasch MS, Knapik SS, Hu Y, Jackson EN, Harpstrite SE, Verghese PB et al.. Clinica chimica acta; international journal of clinical chemistry, 2021-05-17
Topic: Plasma and spinal-fluid biomarkers
Background There is an unmet need for an accessible, less invasive, cost-effective method to facilitate clinical trial enrollment and aid in clinical Alzheimer's disease (AD) diagnosis. APOE genotype affects the clearance and deposition of amyloid-beta (Aβ) with APOE4 carriers having increased risk while APOE2 alleles appear to be protective. Lower plasma Aβ42/40 correlates with brain amyloidosis. In response, C 2 N has developed the PrecivityAD™ test; plasma LC-MS/MS assays for Aβ isoform quantitation and qualitative APOE isoform-specific proteotyping. Methods In accord with CLIA standards, we developed and validated assay performance: precision, accuracy, linearity, limit of detection (LoD), interferences. Results Within-day precision varied from 1.5-3.0% (Aβ40) and 2.5-8.4% (Aβ42). Total (within-lab) variability was 2.7-7.7% (Aβ40) and 3.1-9.5% (Aβ42). Aβ40 quantitation was linear from 10 to 1780 pg/mL; Aβ42 was linear from 2 to 254 pg/mL. LoD was 11 and 2 pg/mL for Aβ40 and Aβ42, respectively. APOE proteotypes were 100% concordant with genotype, while LoD (fM) was much lower than APOE concentrations observed in plasma (mM). Conclusions The PrecivityAD™ assays are precise, accurate, sensitive, and linear over a wide analytical range, free from significant interferences, and suitable for use in the clinical laboratory.
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APA 7th
Kirmess, K. M., Meyer, M. R., Holubasch, M. S., Knapik, S. S., Hu, Y., Jackson, E. N., et al. (2021). The PrecivityAD™ test: Accurate and reliable LC-MS/MS assays for quantifying plasma amyloid beta 40 and 42 and apolipoprotein E proteotype for the assessment of brain amyloidosis. Clinica chimica acta; international journal of clinical chemistry. https://doi.org/10.1016/j.cca.2021.05.011
Vancouver
Kirmess KM, Meyer MR, Holubasch MS, Knapik SS, Hu Y, Jackson EN, et al. The PrecivityAD™ test: Accurate and reliable LC-MS/MS assays for quantifying plasma amyloid beta 40 and 42 and apolipoprotein E proteotype for the assessment of brain amyloidosis. Clinica chimica acta; international journal of clinical chemistry. 2021. doi:10.1016/j.cca.2021.05.011. PMID: 34015303.
BibTeX
@article{kirmess2021-34015303,
author = {Kirmess, K. M. and Meyer, M. R. and Holubasch, M. S. and Knapik, S. S. and Hu, Y. and Jackson, E. N. and Harpstrite, S. E. and Verghese, P. B. and others},
title = {{The PrecivityAD™ test: Accurate and reliable LC-MS/MS assays for quantifying plasma amyloid beta 40 and 42 and apolipoprotein E proteotype for the assessment of brain amyloidosis}},
journal = {Clinica chimica acta; international journal of clinical chemistry},
year = {2021},
doi = {10.1016/j.cca.2021.05.011},
pmid = {34015303},
url = {https://doi.org/10.1016/j.cca.2021.05.011}
}
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Key findings
- APOE genotype affects the clearance and deposition of amyloid-beta (Aβ) with APOE4 carriers having increased risk while APOE2 alleles appear to be protective.
- Results Within-day precision varied from 1.5-3.0% (Aβ40) and 2.5-8.4% (Aβ42).
- Conclusions The PrecivityAD™ assays are precise, accurate, sensitive, and linear over a wide analytical range, free from significant interferences, and suitable for use in the clinical laboratory.
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Study details
- Effect size3.0%; 8.4%; 7.7%
- Evidence strengthLow
How this study scored 43/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, studied in people and randomised / blinded because the record does not state it. We have no data on journal's citation record, 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 25 of the 58 points we could judge it on, which is 43 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Clinica chimica acta; international journal of clinical chemistry) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| 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 | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 3 / 5 | 2021 — within 6 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| 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 | 2 / 2 | Indexed in PubMed (PMID 34015303) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 25 / 58 | Scored on 11 of 20 parts. We have no data for the rest, so they are left out: 25 of the 58 points we could judge it on is 43 out of 100. |
| Total | 43 / 100 | — |
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