Sera of patients with infantile eosinophilic gastroenteritis showed a specific increase in both thymic stromal lymphopoietin and IL-33 levels

An earlier study reported that some cytokines (IL-5 and IL-15) can be detected at increased levels in the blood of adult patients with EGE, as well as those with EoE.3 Availability of blood biomarkers would greatly facilitate the diagnosis of infantile EGE. [...]we tried to find clinically useful biomarkers by searching for cytokines/chemokines with markedly increased serum levels in patients with infantile EGE compared with clinically relevant control subjects. In particular, a polymorphism located near the TSLP locus is reportedly associated with EoE.2 These cytokines are known to be produced by tissue-resident cells in response to various environmental stimuli or cell damage.5 Although previous studies showed serum levels of TSLP, IL-33, or both to be increased in both patients with UC and those with AD,6,7 levels were not high in our patients with UC or AD, despite the fact that their disease severity and inflammation levels were fairly high. Because this group of patients with infantile EGE showed markedly improved weight gain after the start of food elimination and a positive reaction on a chronic tolerance test (daily ingestion of the offending food for 2-3 continuous weeks), the diagnosis of non-IgE-mediated gastrointestinal food allergy8,9 was established.