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Amyloid-Related Imaging Abnormalities (ARIA) in Anti-Amyloid Therapies for Alzheimer's Disease: An Update from the Alzheimer's Association ARIA Workgroup
van Etten ES, et al.. Alzheimer's & Dementia, 2026-04-21
Topic: Amyloid, tau and blood-test diagnosis
This expert workgroup review summarizes what is known about ARIA, the brain-swelling (ARIA-E) and micro-bleeding (ARIA-H) side effect seen with anti-amyloid drugs. Across the Phase 3 trials, ARIA-E/ARIA-H occurred in about 12.6%/17.3% of lecanemab patients and 24%/31% of donanemab patients; most cases are mild or symptom-free and caught on routine MRI, but in roughly 1-2% of cases ARIA has caused permanent disability or death. People with two copies of the ApoE4 gene face 2.5-5 times the risk compared with non-carriers, and the group specifically warns that ARIA symptoms can look like a stroke and must not be mistakenly treated with clot-busting drugs.
Key findings
- ARIA-E/ARIA-H rates: ~12.6%/17.3% with lecanemab, ~24%/31% with donanemab in pivotal trials
- Most ARIA is asymptomatic or mild and detected by scheduled MRI, but ~1-2% of cases result in permanent disability or death
- ApoE ε4 homozygotes have ~2.5-5x higher ARIA risk than non-carriers; concurrent anticoagulant use should generally be avoided due to reported fatal cases; ARIA-E can mimic stroke and must be ruled out before giving clot-busting (thrombolytic) treatment
Why it matters
This workgroup review reports that ARIA occurred in about 12.6%/17.3% of lecanemab patients and 24%/31% of donanemab patients in pivotal trials, with most cases mild or symptom-free but roughly 1-2% causing permanent disability or death. It warns that ApoE ε4 homozygotes face 2.5-5 times the risk and that ARIA symptoms can look like a stroke and must not be mistakenly treated with clot-busting drugs.
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Study details
- Study designsystematic-review
- Effect sizeARIA-E/ARIA-H rates: ~12.6%/17.3% (lecanemab) vs. ~24%/31% (donanemab) in pivotal trials; ApoE4 homozygotes ~2.5-5x higher risk
- Evidence strengthHigh
Limitations
Synthesizes existing trial and case data rather than new original research; real-world ARIA rates outside clinical trials may differ from pivotal-trial rates.
How this study scored 69/100
Published in a leading specialty journal, and it is a systematic review of all the studies on the question. Scored zero for sample size, studied in people and indexed in PubMed 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, still being cited, senior author's track record, institution's track record, multi-centre collaboration and free to read, so those were left out: it earned 43 of the 62 points we could judge it on, which is 69 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Alzheimer's & Dementia) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 12 / 12 | A systematic review of all the studies on the question |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 5 / 5 | 2026 — within 1 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 | A review of other studies — randomisation is not credited here |
| 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 | 0 / 6 | No other study in this library cites it |
| 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 | 0 / 2 | No PubMed ID and no DOI — scores zero (not stated in the record — scored 0) |
| Free to read | — / 2 | Access not recorded — left out of this score |
| Points | 43 / 62 | Scored on 11 of 20 parts. We have no data for the rest, so they are left out: 43 of the 62 points we could judge it on is 69 out of 100. |
| Total | 69 / 100 | — |
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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. This record has no DOI, so the citation leaves it out. 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
van Etten, E. S., et al. (2026). Amyloid-Related Imaging Abnormalities (ARIA) in Anti-Amyloid Therapies for Alzheimer's Disease: An Update from the Alzheimer's Association ARIA Workgroup. Alzheimer's & Dementia.
Vancouver
van Etten ES, et al. Amyloid-Related Imaging Abnormalities (ARIA) in Anti-Amyloid Therapies for Alzheimer's Disease: An Update from the Alzheimer's Association ARIA Workgroup. Alzheimer's & Dementia. 2026.
BibTeX
@article{vanetten2026-912127c4,
author = {van Etten, E. S. and others},
title = {{Amyloid-Related Imaging Abnormalities (ARIA) in Anti-Amyloid Therapies for Alzheimer's Disease: An Update from the Alzheimer's Association ARIA Workgroup}},
journal = {Alzheimer's \& Dementia},
year = {2026}
}