Get help now — free helplines

You can call any of these for free. You do not need a diagnosis, an appointment, or a crisis to call — questions and plain exhaustion are reasons enough.

  • Alzheimer's Association 24/7 Helpline 800-272-3900 24 hours a day, 365 days a year Free, confidential support and information for people with dementia, caregivers, families and the public. Master's-level clinicians. Also Spanish.
  • 988 Suicide & Crisis Lifeline 988 24/7 Call or text 988, or chat at 988lifeline.org. For anyone in emotional distress or a mental-health crisis, including caregivers.
  • Alzheimer's Foundation of America (AFA) Helpline 866-232-8484 9:00 am - 9:00 pm ET, seven days a week Licensed social workers providing support, info and referrals. Also text message and web chat. Text: 646-586-5283

In a medical emergency, call 911. More numbers, and what each line does, on the help page.

Find studies

A note on reading research. One study is rarely the final word.

We try to note the size of a study, whether it was in humans or animals, and how early-stage the finding is. If a summary here doesn't make that clear, treat it with extra caution and check the original source.

TREM2 variants in Alzheimer's disease

✓ Peer-reviewed alzhub usefulness score 85 out of 100. The New England journal of medicine 2012-11-14

Homozygous loss-of-function mutations in TREM2, encoding the triggering receptor expressed on myeloid cells 2 protein, have previously been associated with an autosomal recessive form of early-onset dementia. 4 key findings →

Design: meta-analysis Participants: 1,092 Evidence: high

We identified rare coding variants associated with Alzheimer's disease in a three-stage case-control study of 85,133 subjects. 4 key findings →

Design: case-control study Participants: 85,133 Evidence: moderate

A rare variant in TREM2 (p.R47H, rs75932628) was recently reported to increase the risk of Alzheimer's disease (AD) and, subsequently, other neurodegenerative diseases, i.e. frontotemporal lobar degeneration (FTLD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). 4 key findings →

Design: meta-analysis Participants: 828 Evidence: high

A non-synonymous genetic rare variant, rs75932628-T (p.R47H), in the TREM2 gene has recently been reported to be a strong genetic risk factor for Alzheimer's disease (AD). 4 key findings →

Design: meta-analysis Participants: 32,598 Evidence: high

The TREM2 agonistic antibody AL002 in early Alzheimer's disease: a phase 2 randomized trial

✓ Peer-reviewed alzhub usefulness score 73 out of 100. Nature Medicine 2026-03-05

Triggering receptor expressed on myeloid cells 2 (TREM2) regulates microglial function and is implicated in Alzheimer's disease (AD) pathogenesis. 2 key findings →

Design: phase-2-trial Participants: 381 Evidence: null result

Although studies in animal models suggest that TREM2 is protective against Alzheimer's pathology, its effect on tau pathology and its potential beneficial role in people with Alzheimer's disease is still unclear. 4 key findings →

Design: longitudinal study Participants: 155 Evidence: moderate

Variants of the gene triggering receptor expressed on myeloid cells-2 (TREM2) increase the risk of Alzheimer's disease (AD) and other neurodegenerative disorders. 4 key findings →

Design: clinical trial Evidence: high

Low frequency coding variants in TREM2 are associated with increased Alzheimer disease (AD) risk, while loss of functions mutations in the gene lead to an autosomal recessive early-onset dementia, named Nasu-Hakola disease (NHD). 5 key findings →

Design: case-control study Participants: 180 Evidence: moderate

TREM2 is a transmembrane receptor that is predominantly expressed by microglia in the central nervous system. 4 key findings →

Design: cross-sectional Participants: 1,027 Evidence: moderate

A variant within a DNase hypersensitive site 5' of TREM2, rs9357347-C, associates with reduced AD risk and increased TREML1 and TREM2 levels (uncorrected P = 6.3 × 10 -3 and 4.6 × 10 -2 , respectively). 4 key findings →

Design: meta-analysis Participants: 1,006 Evidence: high

TREM2 is associated with increased risk for Alzheimer's disease in African Americans

✓ Peer-reviewed alzhub usefulness score 67 out of 100. Molecular neurodegeneration 2015-04-10

TREM2 encodes for triggering receptor expressed on myeloid cells 2 and has rare, coding variants that associate with risk for late-onset Alzheimer's disease (LOAD) in Caucasians of European and North-American origin. 4 key findings →

Design: case-control study Participants: 800 Evidence: moderate

A rare coding variant (rs72824905, p.P522R) conferring protection against Alzheimer's disease (AD) was identified in the gene encoding the enzyme phospholipase-C-γ2 (PLCG2) that is highly expressed in microglia. 4 key findings →

Design: longitudinal study Participants: 10,097 Evidence: moderate

A rare TREM2 missense mutation (rs75932628-T) was reported to confer a significant Alzheimer's disease (AD) risk. 4 key findings →

Design: meta-analysis Participants: 89,157 Evidence: high

The rare TREM2 R47H variant exerts only a modest effect on Alzheimer disease risk

✓ Peer-reviewed alzhub usefulness score 65 out of 100. Neurology 2014-09-03

Meta-analysis of the 2 family-based and the 5 case-control cohorts yielded a p value of 0.0029, while the overall summary estimate (using case-control data only) resulted in an odds ratio of 1.67 (95% confidence interval 0.95-2.92) for the association between the TREM2 R47H and increased AD risk. 3 key findings →

Design: meta-analysis Evidence: high

Homozygous mutations in exon 2 of TREM2, a gene involved in Nasu-Hakola disease, can cause frontotemporal dementia (FTD). 4 key findings →

Design: meta-analysis Evidence: high

Soluble TREM2 changes during the clinical course of Alzheimer's disease: A meta-analysis

✓ Peer-reviewed alzhub usefulness score 63 out of 100. Neuroscience letters 2018-08-29

Soluble triggering receptor expressed on myeloid cells 2 (sTREM2) is a potential and novel biomarker of neuroinflammation implicated in the onset and progression of Alzheimer's disease (AD). 4 key findings →

Design: meta-analysis Participants: 82 Evidence: high

TREM2 (triggering receptor expressed on myeloid cells 2) gene variants were reported to increase the risk of Alzheimer's disease (AD) and even other neurodegenerative diseases (frontotemporal dementia (FTD), Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS)), but so far, no definite conclusion has been drawn. 4 key findings →

Design: systematic review Participants: 39 Evidence: high

Our results suggest that the TREM2 p.R47H substitution is a risk factor for frontotemporal dementia and Parkinson's disease in addition to Alzheimer's disease. 4 key findings →

Participants: 609 Evidence: low

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Where “Free full text” comes from

Free full text links and the Full text may need a subscription label come from Unpaywall, Europe PMC and OpenAlex records of free copies, checked 10 Oct 2026. A study with neither is unknown, not paywalled. Show only studies that are free to read

How the 0–100 score works — and why some entries are capped

This is alzhub's own score. It is not an official metric, not an impact factor, and no journal, publisher or ranking body endorses it. We built it so that a reader who is not a scientist can tell a landmark trial from a conference abstract without having to already know the difference. Every point comes from one of 20 components, all of them printed on the study itself, so you can disagree with our arithmetic rather than having to trust the total.

  • Journal tier up to 10 pts
  • Journal's citation record up to 4 pts
  • Study design up to 12 pts
  • Strength of evidence up to 5 pts
  • Peer-review validation up to 10 pts
  • How recent up to 5 pts
  • Sample size up to 4 pts
  • Effect reported up to 3 pts
  • Studied in people up to 3 pts
  • Randomised / blinded up to 2 pts
  • Times cited up to 7 pts
  • Citations per year up to 5 pts
  • Impact for its field and year up to 6 pts
  • Cited by studies here up to 6 pts
  • Still being cited up to 4 pts
  • Senior author's track record up to 4 pts
  • Institution's track record up to 3 pts
  • Multi-centre collaboration up to 3 pts
  • Indexed in PubMed up to 2 pts
  • Free to read up to 2 pts

Journals are placed in ordered tiers, never given a numeric impact factor — we could not verify current impact factors from a source we control, and an invented one would be worse than none. Tier 1 is the top-tier general journals (NEJM, The Lancet, JAMA, Nature, Science, Nature Medicine); tier 2 is the leading specialty journals; tier 3 is every other peer-reviewed journal. A separate part scores how much the journal's own papers are cited, which tells the tier-3 journals apart.

Two rules we don't bend. First, we never fill in a missing value: if a record does not state a sample size or a design, that component scores zero, and if we simply have no data for a part, such as a citation count, that part is left out and the study is scored on the parts we could check. The study card says which. Second, anything that is not a peer-reviewed article is capped at 16/100 and carries a warning chip — so a conference abstract or a company press release can never outrank a peer-reviewed paper, no matter how good it looks.

We rank a rigorous null result — a good trial showing that something does not work — above an early positive finding. Someone deciding whether to buy a supplement is served by that, and the rigour is already counted by the design and journal components.

The score is computed from the published data alone and is reproducible: the same file always yields the same numbers.

See the whole rubric drawn out → — four charts covering all 27,380 studies: how the scores are spread and where the cap bites, which of the 20 components the library is strong and weak on, which subjects rest on stronger evidence, and what kinds of study each subject is actually built from.

What this library is — and isn't

This is a large sample of the Alzheimer's literature, not an exhaustive index of it. It holds 27,380 records, built mostly from automated pulls of Europe PMC (60.6% of the library) and OpenAlex (18.6%), plus smaller pulls from PubMed, Crossref and medRxiv. If a study, a drug, or a finding isn't here, that is not evidence it doesn't exist in the literature — it may simply not have been pulled in yet.

1,032 records (3.8% of the library) are not peer-reviewed — 962 of those are preprints posted before any journal review, and the rest are conference abstracts, regulatory notices and reports. Every study card on this page states its status plainly, and the score above is capped for anything that isn't a peer-reviewed article.

See the full, machine-readable breakdown of this library's coverage →

Newest studies, as a dated timeline →    Atom feed