Auto-immune pancreatitis in children: working guidelines for diagnosis and management

Aim: We aim to develop a working definition and diagnostic approach for AIP in children. Background: Autoimmune pancreatitis (AIP) is an increasingly recognized disease entity, but data in children are limited. Pediatric gastroenterologists relied on adult AIP guidelines but disease presentation and outcome of AIP in children might differ from the adult experience. Methods: Clinical data, imaging, histology, and treatment modalities were collected using 2 different approaches: (1) a systematic literature search and (2) children with an AIP diagnosis from the largest multicenter study of chronic pancreatitis in children (INSPPIRE) and from Cliniques St-Luc (CUSL). We then sought expert opinion from pediatric pancreatologists. Results: We identified 44 AIP cases, 26 from literature review, 14 from the INSPPIRE and 4 from CUSL cohort. The median age at diagnosis was 13.2 years. Abdominal pain (39/44, 87%) and/or obstructive jaundice (20/44, 45%) were the most reported symptoms at diagnosis. Elevated IgG4 levels was seen in only 8/38 (21%). Cross-sectional imaging was abnormal in all children mainly showing hypointense global or focal gland enlargement (35/43, 81%), irregularity of the main pancreatic duct (29/43, 67%) and common bile duct stricture (25/43, 58%). Lymphoplasmacytic inflammation, pancreas fibrosis and ductal granulocyte infiltration were the main histologic findings (18/25, 72%). Children with AIP had a prompt clinical response to steroids. Complications of AIP included impaired exocrine (4/25,16%) and/or endocrine (3/27,11%) function. Conclusion: AIP in children is a distinct subtype of pancreatitis. Based on these observations, we established working guidelines to help identification and management of children with AIP and pave the way for future studies.