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

BACKGROUND: The association between inflammatory bowel disease and joint involvement is well established. There is a paucity of data describing histopathological features of the gut in relation to juvenile idiopathic arthritis (JIA). METHODS: We retrospectively identified 33 (21 male) children aged 3-16 y with JIA (11 with oligoarthritis, 5 with polyarthritis, 8 with systemic onset arthritis, 8 with enthesitis-related arthritis (ERA), and 1 with psoriatic arthritis) with significant gastrointestinal (GI) symptoms who underwent upper and/or lower endoscopy. The histopathological findings were reviewed in addition to presence of autoantibodies and concomitant treatment. RESULTS: The most common GI indications for endoscopy were persistent abdominal pain (14/33 (42%)) and diarrhea (10/33 (30%)). Of the 33 children, 28 (85%) had gut mucosal inflammation, mostly affecting the colon (80%). Active inflammation of the gut was found in 5 of 28 (17%) children, and 15 of 28 (53%) children showed mild nonspecific inflammation. Eight patients (27%) had predominantly an eosinophilic infiltrate. Twenty-six patients had previously received treatment for JIA. There was a negative association with the use of immunomodulators and the presence of eosinophil inflammation. CONCLUSION: The majority of children with JIA and GI symptoms have histological evidence of mild nonspecific inflammation, but some having active colitis and prominent eosinophil infiltrate