Isolated Crohn's Colitis: Is Localization Crucial? Characteristics of Pediatric Patients From the CEDATA-GPGE Registry

Abstract

Introduction: Pediatric patients with inflammatory bowel disease (IBD) are classified into Crohn's disease (CD), ulcerative colitis (UC), and unclassifiable (IBD-U). However, data provide evidence that ileal CD (L1) is distinct from colonic CD (L2). The aim of this study was to investigate the clinical features of isolated Crohn's colitis in a pediatric population.

Material and methods: Children who were prospectively included in the CEDATA-GPGE registry on diagnosis were compared according to the diagnosis of CD with L2 vs. L1 and ileocolonic (L3) involvement pattern as well as IBD-U and UC. The clinical significance of L2 was investigated with regard to extraintestinal manifestations, treatment, surgery, and disease activity.

Results: Fifty-two patients with L2 CD at a median age of 13.4 years (±3.8 SD) were compared with 182 L1 (13.8 ± 2.9 SD), 782 with L3 (12.8 ± 3.3 SD), 653 with UC (12.7 ± 3.8 SD), and 111 patients with IBD-U (11.9 ± 4.7 SD). Bloody stools at diagnosis were more common in L2 (44%) than in L1 (19.7%) and L3 (28.8%), but not as common as in UC (66.5%) and IBD-U (61.3%). Fewer CD patients with L2 (10.2%) received exclusive enteral nutrition therapy (EEN) as induction than patients with L1 (34.3%) and L3 (33.3%). After induction therapy, 42.3% of patients with L2 received immunosuppressants and 21% biologicals during follow-up (L1 56.5/10.5%; L3 59/21%; CU 43.5/11.9%; IBD-U 26.1/12.6%). Extraintestinal manifestations were more frequent in L2 (23.1%) vs. L1 (18.7%), L3 (20.2%), CU (15.8%), and IBD-U (11.7%). The number of patients requiring surgery did not differ within the CD subgroups and was significantly lower in UC and IBD-U. Perianal fistula surgery was significantly more common in L2 (44%) than in L1 (4.8%) or L3 (21.7%). In addition, the frequency of surgery for perianal abscesses was also more frequent in L2 (55.6%) than in L1 (12.7%) or L3 (38.4%).

Conclusions: The consideration of pediatric Crohn's colitis as a distinct disease seems necessary as it is characterized by extraintestinal manifestations (EIMs) with mainly joint involvement and perianal fistulas or abscesses requiring surgery and biologic therapy. Thus, colonic Crohn's disease may have an influence on the therapeutic stratification and should be addressed in further studies.

Keywords: Crohn's colitis; Crohn's disease; IBD; isolated colonic Crohn's; pediatric; ulcerative colitis.

Figure 1

Presence of extraintestinal manifestations during the course of disease. The proportion of patients in the cohort with extraintestinal manifestations were recorded over a 2.5-year period for each subgroup and indicated from diagnosis (0) and for every 6 months (±3 months) of follow-up (L1, blue diamond; L2, orange square; L3, gray triangle; UC, yellow cross; IBD-U, light blue star).

Figure 2

Disease activity from diagnosis to 24 months after. Disease activity was evaluated at diagnosis (0), and for every 6 months (±3 months) of follow-up for each subgroup using the physician global assessment (PGA) and presented as percentage for (A) remission, (B) mild, (C) moderate, and (D) severe activities (L1, blue; L2, orange; L3, gray; UC, yellow; IBD-U, light blue). Significant differences (*p < 0.05) were found for moderate disease activity in L2 after 24 months compared with the other subgroups, respectively.

Figure 3

Fecal calprotectin during the course of disease. Disease activity was evaluated by fecal calprotectin every 6 months for up to 60 months as long as the patients have been followed up. Fecal calprotectin is presented as median for each subgroup (L1, blue diamond; L2, orange square; L3, gray triangle; UC, yellow cross; IBD-U light blue star). Significant differences (p < 0.05) were found for L2 compared to L1*¹, IBD-U*⁵ and L3*³.