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Association between increased levels of amyloid-β oligomers in plasma and episodic memory loss in Alzheimer's disease
Meng X, Li T, Wang X, Lv X, Sun Z, Zhang J, Su F, Kang S et al.. Alzheimer's research & therapy, 2019-10-25
Topic: Plasma and spinal-fluid biomarkers
Objective The objectives of this study were to investigate whether the plasma levels of oligomeric amyloid-β (OAβ) were affected in Alzheimer's disease (AD) and to examine the associations (or possible correlations) between plasma OAβ levels and memory performance. Method Thirty subjects with AD and 28 cognitively normal controls were recruited in the study. The multimer detection system (MDS) was used to measure the levels of OAβ in the plasma. In addition to assessing the general cognitive function with the Mini-Mental State Examination (MMSE), Cognitive Abilities Screening Instrument (CASI), and Alzheimer's Disease Assessment Scale-cognitive portion (ADAS-Cog), the common objects memory test (COMT) was used to examine the episodic memory performance. Pearson's and partial correlation analyses were conducted to explore the associations between cognitive performance and OAβ levels in the plasma. A receiving operating curve (ROC) analysis was used to discriminate between the AD and control groups. Results The plasma OAβ levels in the AD group were significantly higher than those in the control group [1.88 (0.38) ng/ml vs 1.20 (0.40) ng/ml, p < 0.001]. The elevated levels of plasma OAβ showed a strong correlation with cognitive performance in patients with AD, including an inverse correlation with scores on the MMSE (r = - 0.43, p = 0.02), CASI (r = - 0.56, p < 0.01), and the immediate recall (r = - 0.45, p = 0.01), 5-min delayed recall (r = - 0.56, p < 0.01), and 30-min delayed recall (r = - 0.71, p < 0.001) tests of the COMT, and a positive correlation with the ADAS-Cog scores (r = 0.59, p < 0.001). The EDTA plasma Aβ oligomer optical density (OD) value measured using the MDS could discriminate between the AD and control groups with an area under the curve (AUC) of 0.89. The optimal sensitivity and specificity were 82.1% and 90.0%, respectively. Conclusion The elevated levels of OAβ in the plasma distinguished the AD and control groups and were associated with the severity of symptoms, especially memory performance, in patients with AD. Our results suggested that plasma OAβ could potentially be a simple and non-invasive blood-based biomarker for AD diagnosis. Furthermore, longitudinal studies are warranted to explore the application of plasma OAβ levels as a valid diagnostic biomarker in patients with AD.
Key findings
- Results The plasma OAβ levels in the AD group were significantly higher than those in the control group [1.88 (0.38) ng/ml vs 1.20 (0.40) ng/ml, p < 0.001].
- Conclusion The elevated levels of OAβ in the plasma distinguished the AD and control groups and were associated with the severity of symptoms, especially memory performance, in patients with AD.
- Our results suggested that plasma OAβ could potentially be a simple and non-invasive blood-based biomarker for AD diagnosis.
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Study details
- Study designlongitudinal study
- Effect size82.1%; 90.0%
- Evidence strengthModerate
How this study scored 60/100
Published in a peer-reviewed journal, and it is a longitudinal study following the same people over time. Scored zero for 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 35 of the 58 points we could judge it on, which is 60 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Alzheimer's research & therapy) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| 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 | 2 / 5 | 2019 — within 10 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 31651358) |
| Free to read | 2 / 2 | Free to read |
| Points | 35 / 58 | Scored on 11 of 20 parts. We have no data for the rest, so they are left out: 35 of the 58 points we could judge it on is 60 out of 100. |
| Total | 60 / 100 | — |
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APA 7th
Meng, X., Li, T., Wang, X., Lv, X., Sun, Z., Zhang, J., et al. (2019). Association between increased levels of amyloid-β oligomers in plasma and episodic memory loss in Alzheimer's disease. Alzheimer's research & therapy. https://doi.org/10.1186/s13195-019-0535-7
Vancouver
Meng X, Li T, Wang X, Lv X, Sun Z, Zhang J, et al. Association between increased levels of amyloid-β oligomers in plasma and episodic memory loss in Alzheimer's disease. Alzheimer's research & therapy. 2019. doi:10.1186/s13195-019-0535-7. PMID: 31651358.
BibTeX
@article{meng2019-31651358,
author = {Meng, X. and Li, T. and Wang, X. and Lv, X. and Sun, Z. and Zhang, J. and Su, F. and Kang, S. and others},
title = {{Association between increased levels of amyloid-β oligomers in plasma and episodic memory loss in Alzheimer's disease}},
journal = {Alzheimer's research \& therapy},
year = {2019},
doi = {10.1186/s13195-019-0535-7},
pmid = {31651358},
url = {https://doi.org/10.1186/s13195-019-0535-7}
}