Strasser DS, et al. - Researchers studied eosinophils and mast cells extensively in oesophageal biopsies from subjects with active eosinophilic oesophagitis (EoE) and from subjects with EoE in remission, and compared the findings with healthy people using immunohistochemistry and quantitative morphometry. They reported that active EoE was characterised in addition to the well-known tissue eosinophilia by a marked epithelium-restricted mast cell infiltration. It was noted that mast cell infiltration persisted in spite of clinical remission in a subgroup of subjects.