Lymphonodular hyperplasia on the mucosa of the lower gastrointestinal tract in children: An indication of enhanced immune response?

Background: To discover the prevalence and significance of lymphonodular hyperplasia (LNH) of the lower gastrointestinal tract, the authors did a retrospective analysis of a consecutive series of children using colonoscopy to evaluate persistent and severe gastrointestinal symptoms. The authors also sought to discover in more detail how often subjects with LNH of the terminal ileum (TI) or colon show an association with food allergy (FA). Methods: The analysis included a consecutive series of 140 children evaluated at the Oulu University Hospital using colonoscopy, which extended to the TI in 74 of these children. A total of 102 patients underwent gastroduodenoscopy. The disease category was assessed using endoscopic, histopathologic, and clinical information. To diagnose FA, a masked or an open food challenge was administered to all patients who aroused any suspicion of food-related exacerbation of symptoms. Results: Of 140 patients, LNH of the colon was diagnosed in 46 subjects, 9 of 38 patients had colitis, I of 8 patients had Crohn disease, and 36 of the remaining 94 subjects did not have colitis. Twelve patients of the 22 with LNH of the colon (55%) showed concomitant LNH on the bulb of the duodenum. Lymphonodular hyperplasia of the TI was diagnosed in 53 of the 74 subjects in whom TI could be visualized. It was seen in most patients without colitis (80%), in one half the subjects with colitis (48%), and in one quarter of those with Crohn disease (25%). Among the whole study group 37 (26%) could be defined as having FA. It was more prevalent in patients with (52%) than in those without (13%) LNH of the colon (P < 0.001). The presence of LNH in the TI also showed some association with FA (P < 0.05), but less than did LNH of the colon, Conclusion: We consider LNH on the mucosa of the colon or TI common but not an innocent bystander. Significantly related to a diagnosis of gastrointestinal FA in this study, it is an expression of mucosal immune response. If detected on the colon, FA should be considered, whereas if present in TI, it may be related to FA but also to a variety of other immunologically active disease states.