P297 Differences in disease characteristics and treatment exposures between pediatric- and adult-onset Ulcerative Colitis

Abstract

Abstract Background previous studies highlighted differences between pediatric-onset ulcerative colitis (pUC) and adult-onset UC (aUC), showing a more severe phenotype in pUC. However, most studies lacked prolonged follow-up, and some were conducted prior to the biologic era. We utilized a large cohort database to compare disease characteristics and treatment exposures between pUC and aUC. Methods Single-center IBD registry from the Sheba Medical Center was used and included aUC (age ≥ 18 years) and pUC (age ≥ 6 and < 18 years) patients diagnosed between 2000 and 2022. Data were retrieved from the medical record to a computerized and periodically updating registry in a unified manner. Retrieved data included demographics, clinical disease characteristics and phenotype, and prescribed treatments during routine clinical follow-up. We used descriptive statistics, T-test, and chi-square test for between-group analyses. Results This study included 1332 UC patients, of them 682 were females (51.2%, Table 1). The cohort comprised 1058 aUC and 274 pUC patients. The median (IQR) age at diagnosis for pUC was 14.9 (12.5-16.8) years and 31.7 (23.6-48.9) years for aUC. Disease duration and the interval from diagnosis to last follow-up were similar between pUC and aUC, with a median (IQR) disease duration of 8.9 years (4.6-14.2) in pUC and 8.5 (4.5-14.1) in aUC, and a median interval from diagnosis to last follow-up of 7.3 years (3.5-12.3) in pUC and 7.3 years (3.4-13.0) in aUC. Significantly more pUC presented with pancolitis: 59.1% vs. 39.4% in aUC (p<0.00001), (Table 1). During long-term follow-up, treatment exposures also varied significantly between pUC and aUC (Figure 1); 61.3% of pUC were treated with systemic steroids vs. only 42.4% in the aUC group. Thiopurines were used in 40.5% of pUC vs. only 16.7% of aUC, and biological therapy was used in 46.0% of pUC vs. 34.1% of aUC. Time to initiation of biologic treatment was shorter in pUC with a median (IQR) of 33.0 months (15.0-71.3) vs. 36.6 months (15.8-96.1) in aUC (p=0.04). Finally, the number of biologics lines used was also higher in pUC vs. aUC ((mean of 2.1±1.4 vs. 1.8±1.0, p=0.01). Limiting the comparison to only UC patients who presented with pancolitis included 163 pUC and 417 aUC. Within this more severe UC phenotype, exposure to steroids and thiopurines was still significantly higher in pUC vs. pUC, but exposure to a biologic was similar with 54.6% of pUC vs. 50.1% of aUC. Conclusion pUC presents with more pancolitis, considered a more severe form of UC. This more aggressive presentation at diagnosis likely leads to a higher rate of exposure to systemic steroids, thiopurines, and biologics during a median of ~7 years of follow-up.