Long-term Extent Change of Pediatric-Onset Ulcerative Colitis.

Background: Data describing extent change (progression or regression) in pediatric-onset ulcerative colitis (UC) are scarce.
Goal: We aimed to describe extent change in pediatric-onset UC during long-term follow-up and to assess predictors of extent change.
Study: Medical charts of pediatric-onset UC patients with at least 5-year follow-up were analyzed retrospectively. Disease extent was determined using the Paris classification. It was examined at diagnosis and during follow-up at different time points. The impact of possible predictors on extent change including age at diagnosis, gender, clinical manifestations, disease, severity indices, and different therapeutic regimens during disease course was assessed.
Results: Patients (n=134, 55% males) were followed for a median duration of 13.1 (range, 5 to 28) years. Median age at diagnosis was 13.1 (range, 2 to 17.8) years. Of 134 patients, 40.5% had extensive or pancolitis, 33.5% left-sided colitis, and 26% had proctitis at diagnosis. On follow-up (n=117), 45% had unchanged disease extent, 35% experienced extent progression, whereas 20% experienced regression of disease extent. The multivariate Cox models demonstrated that among children with left-sided disease at diagnosis, presence of extraintestinal manifestations (hazard ratio, 5.19; P=0.022), and higher pediatric UC activity index (hazard ratio, 8.77; P=0.008) were associated with extent progression to extensive disease. Predictors of extent regression have not been identified.
Conclusions: Disease extent changes significantly over time in pediatric-onset UC. In our cohort, presence of extraintestinal manifestation and higher pediatric UC activity index score at diagnosis were associated with progression from limited to extensive disease during follow-up.