# The EoE Literature: A Comprehensive Multi-Database Systematic Review

**A four-part synthesis of the eosinophilic esophagitis literature — disease, immune mechanisms, pMHC diagnostics/therapeutics, and targeted translational arms — built on 2,456 DOI-verified references retrieved across PubMed, OpenAlex, and citation-graph expansion, plus a 157-trial ClinicalTrials.gov pipeline analysis.**

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## Scope and honest ceiling

This review was commissioned as "the most exhaustive literature review of EoE," followed by focused reviews of immune mechanisms and the emerging pMHC area, plus targeted translational arms. The honest characterization of what was achieved: **the most comprehensive synthesis attainable from open bibliographic APIs in a single working session** — systematic multi-database retrieval, deduplication, citation-graph expansion, LLM-assisted relevance screening, and evidence tiering, with every cited DOI verified against Crossref. It is not a hand-curated, full-text-read-of-every-paper review (some full texts are paywalled; synthesis is abstract- and metadata-level for those), and it does not claim completeness of the entire ~5,000+ paper EoE corpus. What it *does* provide is a broad, reproducible, tiered evidence base and a referee-grade thematic synthesis with explicit gap analysis.

### Corpus at a glance
- **2,456** unique DOI-verified references total; **2,026** passed relevance screening (430 keyword false-positives excluded).
- Evidence tiers: **248 Tier-1** (landmark/primary), **696 Tier-2** (supporting primary), **1,082 Tier-3** (review/context).
- **1,061** references carry abstracts; **105** were independently retrieved by ≥2 databases.
- Publication years span **1946–2025** (median ~2015).
- Databases: PubMed (biomedical, abstracts+PMC), OpenAlex (scholarly graph, incl. preprints), citation-graph expansion on 23 landmarks; ClinicalTrials.gov (157 EoE interventional trials).
- Retrieval method note: bioRxiv/medRxiv keyword search was unavailable (category+date only), so preprint coverage is via OpenAlex indexing.

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## How to read this review — navigation

The review is delivered as four self-contained parts plus this master document and an evidence-map figure:

| Part | File | Covers |
|---|---|---|
| **I. Disease** | `eoe_review_part1_disease.md` | Definition, epidemiology & rising incidence, natural history/fibrostenosis, clinical presentation, diagnosis (histology, PPI-REE, AGREE criteria), EREFS endoscopy, EGID family, treatment overview, outcomes/QoL |
| **II. Immune mechanisms** | `eoe_review_part2_immune_mechanisms.md` | Eosinophils, mast cells (SIGLEC6⁺ state), CD4/Th2 & peTh2, ILC2, basophils, DC/epithelial antigen presentation, B cells/IgG4, Tregs, epithelium/barrier (DSG1/FLG/SPINK7), alarmins (TSLP/IL-33/IL-13), fibroblasts/remodeling, IFN-γ layer |
| **III. pMHC dx/tx** | `eoe_review_part3_pmhc.md` | Antigen-specific T-cell detection (tetramers/AIM/scTCR-seq), the Hill–Spergel eoeTCR-4 breakthrough (+patent prior-art), presentation≠pathology diagnostic principle, tolerance/anergy therapeutics, celiac/T1D/MS precedents, computational prediction, honest limits |
| **IV. Targeted arms** | `eoe_review_part4_targeted.md` | Genetics/HLA/GWAS, prevention & atopic march (teplizumab template), diagnostic gap, approved+pipeline therapeutics (ClinicalTrials.gov analysis) |
| Evidence map | `eoe_evidence_map.png` | Reference volume by part×tier, temporal depth, claim→evidence-strength gap map |
| Reference library | `eoe_master_reference_library.csv` | All 2,456 references with DOI, year, venue, themes, tier, source databases |

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## Cross-cutting synthesis: what is established, contested, and open

### Established (Tier-1 supported, multi-source)
- **EoE is a chronic, food-antigen-driven, CD4⁺/Th2-mediated disease** with a conserved, IL-13-inducible, treatment-reversible epithelial transcriptome centered on eotaxin-3/CCL26 (Blanchard 2006). 
- **It is progressive:** untreated inflammation drives fibrostenosis, and *diagnostic delay is the dominant modifiable risk factor* for stricture (Schoepfer/Dellon 2013) — the strongest argument for earlier, less-burdensome diagnosis.
- **The mechanism is a wired type-2 circuit:** epithelial alarmins → ILC2/Th2/basophil cytokines → IL-13 epithelial reprogramming → eosinophil recruitment + mast expansion → fibroblast remodeling, with a CD4/antigen-presentation core.
- **The type-2 axis is druggable:** dupilumab (anti–IL-4Rα) is FDA-approved (Dellon 2022), validating IL-4/IL-13, with a deep biologic pipeline behind it.
- **Antigen-specific detection is real and precedented:** gluten-specific T-cell tetramers in celiac (Ráki 2007) and now a validated EoE food-specific TCR (eoeTCR-4, Dilollo/Hill 2025).

### Contested / evolving
- **Eosinophil count vs symptoms:** eosinophil-depleting benralizumab achieved histologic but not full symptom response (2024) — questioning eosinophil count as the sole activity measure.
- **IgG4's role:** clearly elevated in adult EoE, but pathogenic vs bystander is unresolved.
- **The relative weight of the IFN-γ layer** (this project's emphasis) on top of the type-2 core — an emerging, not settled, refinement.
- **Which endotype framework** best stratifies patients for therapy.

### Open (hypothesis-level; the white space)
- **Antigen-specific pMHC *therapeutics* for EoE** — mechanistically motivated (teplizumab, tolerogenic approaches) but not yet demonstrated in EoE.
- **Prevention of EoE onset** — no trial has prevented EoE; the case rests entirely on adjacent-disease proof (LEAP, AIT, teplizumab).
- **Novel non-cytokine targets** (SIGLEC6, IL1RL1/ST2 receptor-side, CCL26/CCR3) — strong preclinical rationale, no clinical validation.

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## Gap analysis — where the evidence is thin (and what each gap rests on)

| Gap | What establishes it | Consequence for the project |
|---|---|---|
| **No EoE-specific prevention trial** | Familial risk quantified (Alexander 2014) but zero interventional prevention studies in EoE | Prevention program is hypothesis-generating; must borrow proof from T1D/allergy |
| **pMHC therapeutics unproven in EoE** | Single validated TCR (eoeTCR-4); all therapeutic pMHC data from other diseases | Tolerance-therapy arm is rationale, not result |
| **Presentation ≠ pathology** | Index-case wheat false-positive; DQ prediction poorly benchmarked | Any diagnostic MUST end in a functional Th2 readout, not binding prediction |
| **Diagnostic prior-art is patented** | Hill–Spergel functional-assay-to-name-food patent | Commercialization bounded; project contribution is a downstream refinement |
| **Eosinophil count ≠ symptom burden** | Benralizumab 2024 dissociation | Histologic endpoints insufficient; need symptom/functional co-primary |
| **Novel targets lack clinical data** | SIGLEC6/IL1RL1/CCL26 preclinical only | Protein-design leads are early-stage hypotheses |

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## Standing disclaimers
- **Computational predictions are priors, not results.** All epitope/binding predictions (netMHCIIpan, mhcnuggets) are hypothesis-generating and require functional confirmation.
- **Prior art / patent.** The functional antigen-specific-T-cell diagnostic paradigm (Hill–Spergel) is foundational and patent-protected; this project's contributions are positioned as downstream refinements.
- **No clinical validation.** Nothing here is validated for clinical use; therapeutic and prevention concepts require formal trials and regulatory review.
- **This is a hackathon research synthesis**, not a clinical guideline. Clinical decisions must be made by qualified clinicians.

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*Companion documents in this project: `atopic_march_prevention_review.md` (detailed prevention synthesis), `eoe_food_trigger_dx_design.md` (diagnostic design + index-case calibration), and the Phase 1–4 omics/target-discovery reports. Full reference list with tiers and theme tags: `eoe_master_reference_library.csv`.*