Biomarkers Show Promise as Minimally Invasive Diagnostic Tools for Eosinophilic Esophagitis in Young Patients

A diagnosis of eosinophilic esophagitis (EoE) is established by upper endoscopy with at least one esophageal biopsy showing more than 15 eosinophils per high-power field (hpf). Serial upper endoscopic procedures with esophageal biopsies are also the gold standard for assessing the efficacy of ongoing therapies in patients with EoE. Blood biomarkers based on the pathogenesis of EoE have been proposed as a minimally invasive, lower-cost modality for diagnosing EoE and assessing disease activity in clinical practice, as an alternative to peak eosinophil counts in esophageal biopsy specimens. Non-invasive or minimally invasive biomarkers could also provide an answer to the problem of unevenly distributed eosinophils, which can lead to sampling errors and false negatives.

“There are candidate biomarkers based on the pathogenesis of EoE, however, none have yet been validated in the pediatric population,” according to Teresa Y. Oh, MD, a gastroenterologist in the Pediatrics Department at Emory University, in Atlanta, Ga. Oh and colleagues designed a prospective cohort study to assess the utility of minimally invasive blood biomarkers for the diagnosis of EoE in patients aged 0 to 21 years. The investigators assessed plasma levels of different eosinophil-derived biomarkers in children and adolescents with active EoE, defined by histologic evidence of 15 or more peak eosinophils per hpf, and compared them to biomarker levels in healthy children and in those with other atopic diseases. The initial pilot study included 14 pediatric patients with EoE and 37 children and adolescents who had other atopic diseases, including asthma, eczema, allergic rhinitis, and/or IgE-mediated food allergies, but no diagnosis of EoE. Twenty children and adolescents who did not have EoE or other atopic diseases were assigned to the control group.

Previously frozen plasma samples, obtained from peripheral blood, were analyzed with the use of enzyme-linked immunosorbent assays. The analysis showed that patients with EoE had higher median plasma levels of eosinophil-derived neurotoxin, major basic protein-1, and eosinophil cationic protein compared with children in the control group and those with other atopic diseases. The results were presented in a poster session at Digestive Disease Week 2024.

The levels of plasma charcot-leyden crystal protein/galectin-10 and eotaxin-3, two other biomarkers investigated in the study, were not significantly different between the three groups. However, a study with a larger cohort, currently in the process of recruiting participants, will provide more details about the utility of the studied biomarkers. “This pilot study validated several novel eosinophil-associated plasma biomarkers in distinguishing EoE from both healthy and atopic controls,” the authors concluded. “Potentially, these may be used as minimally invasive tests in diagnosing EoE. Future analysis will include random forest analyses to identify the predictive ability of biomarker panels in diagnosing EoE.”