229 IBD phenotype on disease presentation and early disease-course in pediatric patients in Croatia: data from the Croatian national registry

Aims of this study were to determine the phenotype of pediatric inflammatory bowel disease (IBD) in patients in Croatia at the time of disease presentation, evaluate diagnostic and therapeutic approaches and investigate early disease-course in one-year follow-up. During a one-year time period (June 1st, 2016 to May 31st, 2017), children and adolescents younger than 18 years of age in Croatia with newly diagnosed IBD were prospectively recruited into Croatian national registry. Data on disease location and behavior (according to Paris classification), diagnostic evaluation and therapy used for inducing and maintaining remission were collected. One-year follow-up data examined relapse rates, as well as modification of medical therapy. A total of 51 newly diagnosed patients were recruited: 19 (37.3%) Crohn’s disease (CD), 28 (54.9%) ulcerative colitis (UC) and 4 (7.8%) IBD – unclassified (IBD-U). Most common location in CD was ileocolonic (L3) disease in 52.6%, followed by distal 1/3 ileal disease (L1) in 31.6%. Patients with UC most commonly had pancolitis (E4) (53.6%), and 7.1% presented with ever severe form of the disease (S1). The recommended complete diagnostic algorithm was performed only in 29.4% of our patients. First line therapy used in CD was exclusive enteral nutrition (EEN) for remission induction (84.2%) and azathioprine for remission maintenance (73.7%). In patients with UC, aminosalicylates were the most common drug used (89.3%). By the end of the first year 41.2% of CD and 53.9% of UC patients had a relapse and required escalation of treatment. Median time to the first relapse was 5 (5-11) months. Following potential risk factors for relapse were examined: age (p = 0.769), gender (p = 0.091), Z – score body mass index for age (p = 0.914), Z – score height for age (p = 0.087), Pediatric Crohn’s Disease Activity Index (p = 0.947), Pediatric Ulcerative Colitis Activity Index (p = 0.245), EEN (p = 0.605), but none of them were statistically significant. Our data confirm extensive intestinal involvement in pediatric IBD and relatively high relapse rate during the first year of follow-up. More effort should be invested on the national level to implement more stringent adherence to the current European guidelines.