[636] The Significance of Mucosal Eosinophilia in the Pediatric Colon
SM El Jamal, T Gibbons, E Davis, AG Saad. University of Arkansas for Medical Sciences, Little Rock, AR
Background: The exact number and pattern of colonic mucosal eosinophilia (CME) that is often associated with colonic disorders is largely unknown. The aim of this study is to evaluate the significance of CME in the pediatric population.
Design: Pediatric patients with colonic biopsies interpreted as normal (control) or increased mucosal eosinophilia (patients) seen in the pediatrics service are included in this study. Clinical presentations included abdominal pain, vomiting, abnormal bowel movements, and blood in stool. In each part of the colon, eosinophils were evaluated for various parameters including number, location (superficial vs. basal), distribution [clustering (EC) vs. scattered] and intraepithelial eosinophils (IEE). The number of eosinophils was generated by manually counting the number of eosinophils per hot spot at 40X magnification. A cluster of eosinophils is defined as a cluster of ≥5 eosinophils.
Results: The study consisted of 29 patients (14 patients and 15 controls) with complete clinical follow-up. Details of histologic findings are in table 1. Follow-up of the patients group found that 10 patients met the criteria of recurrent abdominal pain (RAP), 2 patients developed IBD and 2 patients were found to have parasitic infection. Of the control group, 13 patients were found to have extracolonic pathology such as H. pylori infection and gastro-esophageal reflux disorder; one patient developed IBD and another was found to have parasitic infection. Analysis of the data showed strong correlation between the presence of EC and IEE and the development of colonic diseases. the number of CME was a poor predictor of colonic diseases. There was no correlation between the distribution (superficial vs. basal) of eosinophils and the development of colonic diseases.
| Parameter | Patients (14) | Controls (15) |
| Eosinophilic clustering | 13 (92.8%) | 1 (6.7%) |
| Epithelial eosinophils | 10 (71.4%) | 3 (20%) |
| Basally located eosinophils | 5 (35.7%) | 6 (40%) |
| Superficially located eosinophils | 4 (28.6%) | 5 (3.3%) |
| Number of eosinophils (mean ± SD): | ||
| Right colon (cecum and ascending) | 31.2 ± 12.1 | 24.1 ± 8.9 |
| Transverse colon | 29.9 ± 10.9 | 24.3 ± 6.8 |
| Left colon (descending and rectosigmoid) | 30.8 ± 19.5 | 21.4 ± 6.1 |