Biomarkers of T2 inflammation in the diagnosis and monitoring of eosinophilic esophagitis in children

BACKGROUND: Eosinophilic esophagitis is an immune-mediated disease associated with activation of T2 inflammation in esophageal tissues. Monitoring eosinophilic esophagitis activity in children requires invasive diagnostic methods using general anesthesia. The study of T2 inflammatory biomarkers is currently not a generally accepted diagnostic method but may be an informative and more accessible way to monitor eosinophilic esophagitis in children over time. AIM: Comparative assessment of serum markers of T2 inflammation in children with eosinophilic esophagitis and other T2-associated diseases and determination of the potential of these biomarkers for monitoring the course of eosinophilic esophagitis. MATERIALS AND METHODS: A cross-sectional, single-center comparative study included patients with eosinophilic esophagitis and other T2-associated diseases without eosinophilic esophagitis aged under 18 years. All patients underwent clinical and laboratory tests, esophagogastroduodenoscopy with morphological examination of esophageal mucosa biopsy specimens. Eosinophilic esophagitis activity was assessed using the I-SEE index. The concentrations of cytokines involved in the T2 type immune response were determined in blood serum using enzyme immunoassay. RESULTS: The study included 80 patients: 40 patients with eosinophilic esophagitis, the comparison group included 40 children with other T2-associated diseases without eosinophilic esophagitis. Male patients were statistically significantly more common in the eosinophilic esophagitis group (p = 0.004). Immunoglobulin E- and non-immunoglobulin E-mediated food allergy were statistically significantly more common in patients with eosinophilic esophagitis (p = 0.003 and p = 0.002, respectively). The levels of interleukin 4 and 13 were statistically significantly higher in the comparison group (p 0.001). However, after dividing patients with eosinophilic esophagitis into subgroups by the degree of disease activity, in patients with low eosinophilic esophagitis activity, the level of interleukin 4, 13 and eotaxin-3 was statistically significantly lower (p 0.001). The level of eosinophil peroxidase was statistically significantly higher than in the comparison group and in patients with higher eosinophilic esophagitis activity and (p = 0.045 and p = 0.030, respectively). All patients with eosinophilic esophagitis complicated by esophageal stenosis had 15 or more points on I-SEE. The level of interleukin 33 in patients with esophageal stenosis was statistically significantly higher than in patients without stenosis (p 0.001). CONCLUSION: Biomarkers of T2 inflammation demonstrated statistical significance in relation to the activity and severity of eosinophilic esophagitis. The obtained results highlight the high potential of using these biomarkers as a minimally invasive method for dynamic monitoring of disease activity, opening up new possibilities for a personalized approach to the treatment of eosinophilic esophagitis in children.