Terminal ileitis: etiology and predictors of pediatric Inflammatory Bowel Disease

Abstract

Introduction: Terminal ileitis is an inflammatory reaction that can be caused by multiple conditions including Inflammatory Bowel Disease (IBD). While the natural history of isolated terminal ileitis is well-documented in adults, there is limited research in children. We aim to characterize a cohort of pediatric patients with confirmed isolated terminal ileitis by ultrasound followed at a tertiary hospital. Methods: We conducted a retrospective observational study of children (<18 years) with isolated terminal ileitis followed in a Pediatric Gastroenterology outpatient appointment from 2017 to 2019. Exclusion criteria included previous IBD diagnosis and loss of follow-up. We collected demographic and clinical data, fecal calprotectin, results of blood and imaging tests. Logistic regression and ROC curve were used to establish laboratory variables cut-off points. Results: We included 82 children, 45 (54.9%) males, mean age 12.8 ± 3.5 years. During follow-up, 33 (40.2%) patients were diagnosed with IBD and 49 (59.8%) with other diseases. IBD patients were predominantly referred by primary health care (30.3%) and other specialties (48.5%), whereas non-IBD patients were mainly referred by the emergency department (63.3%) (p<0.001). The absence of acute abdominal pain, presence of bloody stools, weight loss, asthenia, high erythrocyte sedimentation rate (ESR), hypoalbuminemia, high C-reactive protein (CRP) and fecal calprotectin were significantly associated with IBD. Multivariate regression identified ESR and weight loss as independent variables in predicting the risk of having IBD. Discussion/Conclusion: Terminal ileitis frequently prompts referrals to pediatric gastroenterology outpatient clinics. In our study, we highlight that the presence of red flags like asthenia, weight loss and bloody stools could help identifying patients with IBD. Despite model limitations, incorporating albumin, ESR, and fecal calprotectin showed potential in predicting IBD risk over time. These findings can contribute to define a reliable model to differentiate those requiring minimal non-invasive approach from those warranting a more prolonged investigation.