P177. Phenotypic and therapeutic differences in Crohn's disease depending on age at diagnosis
E. Leo Carnerero, G. Ontanilla Clavijo, C. Trigo Salado, M.D. De La Cruz Ramirez, A. Araujo Miguez, J.M. Herrera Justiniano, J.L. Marquez Galan, HU Virgen del Rocío, UGC Digestive Diseases, Seville, Spain
To assess potential differences in phenotypic characteristics, use of immunosuppressive treatment and need for surgery between patients with Crohn's disease (CD) classified into groups A1 and A3 by age at diagnosis according to the Montreal classification.
Retrospective analysis of 328 patients with CD, including patients diagnosed below the age of 17 years (A1, n 45) and over 40 (A3, n 67). Within these groups, differences depending on whether age at diagnosis was younger or older than 10 years (A1a and A1b respectively) or younger and older than 60 years (A3a and A3b) were assessed. Variables collected: demographic and phenotypic characteristics of CD (Montreal classification), smoking, follow-up time, use of immunosuppressants (IS) or biologics, and need for surgery (intestinal resection).
Mean follow-up time 9.68 years, longer in A1 patients (10.9 vs 6.9 years, p 0.007). There were more smokers in the A3 group (62.7% vs 31%, p < 0.001).
Extent of disease: ileocolic location was more common in A1 group as compared to A3 (68.9% vs 27.7%; p < 0.0001), while the ileal (26.7% vs 46.2%; p 0.03) and pure colonic location (4.4% vs 26%; p 0.004) predominated in the A3 group. A1 patients also had a significantly greater involvement of upper segments (24.4% vs 6%; p < 0.001).
Fistulizing pattern was more common in A1 (26.7% vs 13.4%; p 0.031), but inflammatory pattern was the most common in both groups. No differences in perianal disease were seen.
A1 patients were treated more frequently with immunosuppressants (97.8% vs 55.2%; p < 0.001). However, although A1 group required surgery more frequently than A3 (42.2% vs 28.4%), the difference was not statistically significant.
No differences were found within A1 group between ileal and colonic locations, but involvement of upper segments (44% vs 14.9%; p < 0.001) and stenosing pattern were more common in the A1a subgroup (55.6% vs 19.1%; p 0.009) than A1b patients. Such differences were not seen between A3a and A3b subgroups.
As compared to CD diagnosed over 40 years of age, diagnosis at a pediatric age is related to more extensive involvement, increased risk of ileocolic disease and involvement of upper segments, with the latter being more common the younger the patients at diagnosis. In addition, early ages are related to an increased incidence of the penetrating pattern, although a detailed analysis in younger patients reveals predominance of stenosing pattern. However, although the risk of surgery is greater in A1 group, there are no significant differences despite a longer follow-up time, possibly because of almost continuous and early use of immunosuppressants in pediatric age due to frequent involvement of upper segments and, above all, minimization of steroid use.