Aim: The aim of the study was to measure the number of eosinophils per high-power field (eos/HPF) according to age, organs, and clinical symptoms and to compare the results to histological characteristics of the upper digestive tract mucosa in children.
Patients and methods: A systematic prospective assessment of 284 esophagus, 342 antrum, 453 corpus, and 167 duodenum biopsies was carried out in 316 girls and 366 boys referred for endoscopy (median age 9 months), eos/HPF, and histological analysis.
Results: Counts (mean-max SD) were as follows: esophagus 1.73 to 50 eos/HPF (5.35), antrum 3.27 to 40 (4.7), corpus 2.11 to 38 (3.76), and duodenum 4.80 to 46 (7.7). Counts >15 eos/HPF were found in 2.8% esophagi, 3.5% corpora, 4.9% antra, and 10.7% duodena. Duodenal eos/HPF were significantly higher than those of esophageal, corporeal, and antral. Mucosal eos/HPF increased with age in esophagus and antrum. The highest esophageal eos/HPF were significantly associated with recurrent abdominal pain, and with anemia in antrum, corpus, and duodenum. Major and/or minor histological features of eosinophilic esophagitis were seen in 9 of 10 esophagi with 5 to 15 eos/HPF and 7 of 8 esophagi with >15 eos/HPF. Eosinophils per high-power field were significantly correlated with histological antral and corporeal gastric inflammation. Helicobacter pylori-positive children had higher eosinophils per high-power field than H pylori negative ones both in esophagus and in antrum.
Conclusions: The present study shows that in a western European country mucosal hypereosinophilia is rare. Mucosal eosinophil counts increase from esophagus to duodenum, and also with age in esophagus and antrum. The highest eos/HPF in the esophagus are associated with recurrent abdominal pain and in the corpus, antrum, and duodenum with anemia. Features of eosinophilic esophagitis are rare but detectable in association with counts as low as 6 eos/HPF.