Quantity and Distribution of Eosinophils in the Gastrointestinal Tract of Children

Abstract

There are a lack of data on the quantity and location of eosinophils in the gastrointestinal tract of healthy individuals. Accordingly, we examined gastrointestinal biopsies obtained during endoscopic evaluation of pediatric patients. Biopsies were previously interpreted as having no diagnostic abnormality. The presence of extracellular eosinophil constituents and the quantity of eosinophils in atopic versus nonatopic individuals was determined. In the esophagus, eosinophils were present in only 2.7% of high-power fields (hpf), with a mean value of 0.03+/-0.10 eosinophils/hpf (mean+/-standard deviation) and a maximum of 1 eosinophil/hpf. Examination of the antrum and fundus revealed similar numbers of eosinophils in the lamina propria (1.9+/-1.3 and 2.1+/-2.4 eosinophils/hpf, respectively), with no eosinophils observed in the surface epithelium. In the small intestine, there were 9.6+/-5.3 (maximum, 26 eosinophils/hpf) and 12.4+/-5.4 eosinophils/hpf (maximum, 28 eosinophils/hpf) in the intercryptal lamina propria of the duodenum and ileum, respectively. The number of eosinophils in the surface epithelium and crypt epithelium was minimal. In the large intestine, the highest concentration of eosinophils was observed in the cecum (20.3+/-8.2 eosinophils/hpf; maximum, 50 eosinophils/hpf), and there were lower concentrations in the transverse and sigmoid colon (16.3+/-5.6 and 8.3+/-5.9 eosinophils/hpf, respectively). The percentage of fields demonstrating extracellular eosinophil granules in all gastrointestinal segments was 70% to 93%, and extracellular granules were most numerous at the edge of the biopsy (P<0.05). Atopic and nonatopic patients had comparable numbers of eosinophils. These data establish baseline gastrointestinal eosinophil values in pediatric patients without apparent pathological disease.

Gastrointestinal Eosinophilia

“…While the normal esophagus is devoid of eosinophils, the rest of the gastrointestinal tract contains readily detectable eosinophils. [54] Thus, differentiation of EGID from the normal condition relies on several factors including (1) eosinophil quantification (and comparisons to normal values at each medical center); (2) the location of eosinophils (e.g. their presence in abnormal positions such as the intra-epithelial and intestinal crypt regions); (3) associated pathological abnormalities (e.g.…”

Histopathological features of gastrointestinal mucosal biopsies in children with juvenile idiopathic arthritis

“…A histological finding of eosinophil infiltration (six cells-high power field (HPF)) in the lamina propria was thought to be a useful threshold for diagnosis of food protein-induced proctocolitis (31,32). However, DeBrosse et al (33) recently described that eosinophils (mean 16-20 cells-HPF) were normally observed in the GI tract of control children, especially in the colon. Functional studies of eosinophilic GI disorders are lacking and much needed to understand the physiology and pathophysiological roles of eosinophils in the GI tract (34).…”

Origin, regulation and physiological function of intestinal oeosinophils

“…Prenatal mice have eosinophils located in similar regions and concentrations as observed in adult mice, providing evidence that eosinophil homing into the gastrointestinal tract occurs independent of endogenous flora [47]. In humans, the appendix, cecum and ascending colon contain the highest concentration of eosinophils in the gastrointestinal tract [48,49]. Interestingly, the number of eosinophils found in normal colon mucosa is influenced by geography, as there was a 35-fold increase in the number of eosinophils counted in colonic mucosal biopsy samples from asymptomatic patients in New Orleans compared to Boston [50].…”