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57/100

✓ Peer-reviewed alzhub usefulness score 57 out of 100. Genetics

Topic: Amyloid, tau and blood-test diagnosis

Objective To understand the time course of β-amyloid (Aβ) deposition in the brain, which is crucial for planning therapeutic trials of Aβ-lowering therapies in Alzheimer disease (AD). Methods Two samples of participants from the Alzheimer's Disease Neuroimaging Initiative were studied with [ 18 F]Florbetapir (FBP) Aβ PET and followed for up to 9 years. Sample A included 475 cognitively normal (CN) older people and those with mild cognitive impairment (MCI) and AD and sample B included 220 CN Aβ- individuals. We examined the trajectory of FBP over time in sample A and the incidence rate of conversion from negative to positive Aβ PET scans in sample B. Results The relationship between time and brain Aβ was sigmoidal, taking 6.4 years to transition from amyloid negative to positive and another 13.9 years to the onset of MCI. Aβ deposition rates began to slow only 3.8 years after reaching the positivity threshold. The incidence rate for scan positivity was 38/1,000 person-years, and factors associated with conversion were age, baseline FBP, and being a female APOE ε4 carrier. Among CN Aβ- individuals, FBP slopes were associated with rates of memory decline and brain tau measured with [ 18 F]Flortaucipir PET 5 years after baseline. Conclusions Lowering brain Aβ must be accomplished early in the evolution of AD. Transitions of PET scans from Aβ- to Aβ+ should be predictable, and it is reasonable to expect that lowering rates of Aβ even in early stages could produce clinically significant benefits.

Cite this study APA, Vancouver, BibTeX · download .bib or .ris

APA 7th

Jagust, W. J., Landau, S. M., & Alzheimer's Disease Neuroimaging Initiative. (2021). Temporal Dynamics of β-Amyloid Accumulation in Aging and Alzheimer Disease. Neurology. https://doi.org/10.1212/wnl.0000000000011524

Vancouver

Jagust WJ, Landau SM, Alzheimer's Disease Neuroimaging Initiative. Temporal Dynamics of β-Amyloid Accumulation in Aging and Alzheimer Disease. Neurology. 2021. doi:10.1212/wnl.0000000000011524. PMID: 33408147.

BibTeX

@article{jagust2021-33408147,
  author  = {Jagust, W. J. and Landau, S. M. and {Alzheimer's Disease Neuroimaging Initiative}},
  title   = {{Temporal Dynamics of β-Amyloid Accumulation in Aging and Alzheimer Disease}},
  journal = {Neurology},
  year    = {2021},
  doi     = {10.1212/wnl.0000000000011524},
  pmid    = {33408147},
  url     = {https://doi.org/10.1212/wnl.0000000000011524}
}

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Key findings

Results The relationship between time and brain Aβ was sigmoidal, taking 6.4 years to transition from amyloid negative to positive and another 13.9 years to the onset of MCI.
The incidence rate for scan positivity was 38/1,000 person-years, and factors associated with conversion were age, baseline FBP, and being a female APOE ε4 carrier.
Among CN Aβ- individuals, FBP slopes were associated with rates of memory decline and brain tau measured with [ 18 F]Flortaucipir PET 5 years after baseline.
Transitions of PET scans from Aβ- to Aβ+ should be predictable, and it is reasonable to expect that lowering rates of Aβ even in early stages could produce clinically significant benefits.

Why it matters

Using amyloid PET scans followed for up to 9 years, this study found that the transition from amyloid negative to positive took about 6.4 years and another 13.9 years to the onset of mild cognitive impairment, with deposition rates slowing only 3.8 years after reaching positivity. The authors conclude that lowering brain amyloid must be done early in the disease process, but this observational study does not itself test a treatment.

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Study details

Participants475
Evidence strengthLow

How this study scored 57/100

Published in a leading specialty journal. Scored zero for study design, effect reported and randomized / blinded because the record does not state it. We have no data on senior author's track record, so that was left out: it earned 55 of the 96 points we could judge it on, which is 57 out of 100.

Component	Points	Why
Journal tier	9 / 10	Tier 2 — leading specialty journal (Neurology)
Journal's citation record	4 / 4	Neurology: journal h-index 525 (OpenAlex, 2026-10-29)
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	2 / 4	475 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)
Randomized / blinded	0 / 2	No randomization or blinding stated — scores zero (not stated in the record — scored 0)
Times cited	5 / 7	Cited 122 times (OpenAlex, 2026-10-10)
Citations per year	3 / 5	17.4 citations a year over 7 year(s) since 2021
Impact for its field and year	4 / 6	Cited 11.6× the average for papers of its field and year (OpenAlex FWCI)
Cited by studies here	3 / 6	Cited by 11 other studies in this library
Still being cited	3 / 4	Cited 74 times in 2024–2026 (2026 still in progress; OpenAlex)
Senior author's track record	— / 4	Senior author's record not available — left out of this score
Institution's track record	2 / 3	University of California, Berkeley: institution h-index 2,012 (OpenAlex)
Multicenter collaboration	1 / 3	OpenAlex lists 2 institution(s) in 1 country
Indexed in PubMed	2 / 2	Indexed in PubMed (PMID 33408147)
Free to read	0 / 2	Behind a paywall — scores zero
Points	55 / 96	Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 55 of the 96 points we could judge it on is 57 out of 100.
Total	57 / 100	—

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