Crohn's disease in a Southern European country: Montreal classification and clinical activity

Background: Given the heterogeneous nature of Crohn's disease (CD), our aim was to apply the Montreal Classification to a large cohort of Portuguese patients with CD in order to identify potential predictive regarding the need for medical and/or surgical treatment. Methods: A cross-sectional study was used based on data from an on-line registry of patients with CD. Results: Of the 1692 patients with 5 or more years of disease, 747 (44%) were male and 945 (56%) female. On multivariate analysis the A2 group was an independent risk factor of the need for steroids (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.1-2.3) and the A1 and A2 groups for immunosuppressants (OR 2.2; CI 1.2-3.8; OR 1.4; CI 1.0 -2.0, respectively). An L3+L3₄ and L₄ location were risk factors for immunosuppression (OR 1.9; CI 1.5-2.4), whereas an L1 location was significantly associated with the need for abdominal surgery (P = 0.001). After 20 years of disease, less than 10% of patients persisted without steroids, immunosuppression, or surgery. The Montreal Classification allowed us to identify different groups of disease severity: A1 were more immunosuppressed without surgery, most of A2 patients were submitted to surgery, and 52% of L1+L1₄ patients were operated without immunosuppressants. Conclusions: Stratifying patients according to the Montreal Classification may prove useful in identifying different phenotypes with different therapies and severity. Most of our patients have severe disease.