S1042 Diagnostic and Therapeutic Monitoring of Eosinophilic Esophagitis: A Systematic Review and Meta-Analysis of Non-invasive Biomarkers

Introduction: A chronic, immune-mediated esophageal condition, eosinophilic esophagitis (EoE), calls for repeated disease activity and therapeutic response evaluation. Although endoscopy with biopsy is still the diagnostic gold standard, its invasibility and cost restrict frequent use. Noninvasive biomarkers, such as eosinophil-derived neurotoxin, eosinophil cationic protein, serum IgG4, periostin, mast cell tryptase, and exhaled nitric oxide, have been alternatively proposed as diagnostic and monitoring tools. Our objective was to evaluate their clinical value and diagnostic accuracy in tracking treatment response and identifying histologically active EoE. Methods: We systematically searched PubMed, Embase, and Cochrane CENTRAL from inception through April 2025. We included clinical trials comparing noninvasive biomarkers' value in EoE against histologic reference criteria (≥15 eosinophils per high‐power field [eos/hpf]). Inverse variance weighting technique was used to pool the data, and random effects model was applied to explain heterogeneity among the studies. Results: Although 16 studies met the inclusion criteria, only 3 were randomized controlled trials evaluating active intervention versus placebo for changes in biomarker levels and thus met the specific requirements for inclusion in our analysis. Mean percentage change for eotaxin-3 between intervention and placebo is -51.67 (95% confidence interval [CI] -60.01 to -43.33; P < 0.0001; I² = 0%), and for TARC (CCL-17) between intervention and placebo is -22.82 (95% CI -30.31 to -15.34; P < 0.0001; I² = 0%), indicating that intervention significantly lowered eotaxin-3 and TARC (CCL-17) levels compared to placebo. There is no heterogeneity among included studies, indicating consistent treatment effects among included studies. Conclusion: Several noninvasive biomarkers, especially eotaxin-3 and TARC (CCL-17), showed clinically and statistically significant drops with effective treatment. This supports their use in tracking disease activity in EoE. While these biomarkers do not yet replace endoscopy, they offer valuable adjunctive tools to assess treatment response and reduce procedural burden in clinical practice and will need further studies to evaluate their use.