Complicated disease and response to initial therapy predicts early surgery in paediatric Crohn's disease: results from the Porto Group GROWTH study.

INTRODUCTION: The ability to predict risk for poor outcomes in Crohn's disease (CD) would enable early treatment intensification. We aimed to identify children with CD with complications at baseline and throughout the study period who are at risk for surgery two years from diagnosis.

MATERIAL AND METHODS: Newly diagnosed children with CD were enrolled into a prospective, multicentre inception cohort. Disease characteristics and serological markers were obtained at baseline and week 12 thereafter. Outcome data including disease activity, therapies, complications, and need for surgery were collected through 104 weeks. Chi-square automatic interaction detection (CHAID) algorithm was used to develop a prediction model for early surgery.

RESULTS: Of 285 children enrolled, 31(10.9%) required surgery within two years. Multivariate analysis identified stricturing disease at baseline (OR 5.26, 95% CI 2.02 - 13.67 (p=0.001)), and Paediatric Crohn's Disease Activity Index (PCDAI) >10 at week 12 (OR 1.06, 95% CI 1.02 - 1.10 (p=0.005) as key predictors for early surgery. CHAID demonstrated that absence of strictures at diagnosis (7.6%), corticosteroid-free remission at week 12 (4.1%), and early immunomodulator therapy (0.8%) were associated with the lowest risk of surgery, while stricturing disease at diagnosis (27.1%, P<0.001) or elevated PCDAI at week 12 (16.7%, p=0.014) had an increased risk of surgery at follow-up. Anti-OmpC status further stratified high-risk patients.

DISCUSSION: A risk algorithm using clinical and serological variables at diagnosis and week 12 can categorise patients into high- and low- risk groups from diagnosis.

FUNDING: A.L Thrasher foundation, Catherine McEwan foundation, and the Porto group of ESPGHAN.