Development and Validation of a Novel Prediction Model for Differential Diagnosis Between Crohn's Disease and Intestinal Tuberculosis.

Background: Although colonoscopy is useful for differentiating between Crohn's disease (CD) and intestinal tuberculosis (ITB), the technique has limitations. We developed a practical prediction model for differentiating between CD and ITB using laboratory and radiologic parameters and colonoscopic characteristics.
Methods: We prospectively enrolled 80 patients newly diagnosed with CD (n = 40) and ITB (n = 40). We developed a new prediction score by integrating colonoscopic, laboratory, and radiologic parameters. The score's predictive ability was validated on an additional 37 patients.
Results: The accuracy of colonoscopic scoring for differentiation was 81.2% (65/80), with 65.0% sensitivity for CD and 97.5% for ITB. In multivariate analysis, positive IgA and/or IgG anti-Saccharomyces cerevisiae antibody and involvement of the proximal intestine were the independent laboratory and radiologic parameters for CD, and positive QuantiFERON-TB Gold In-Tube Test and typical pulmonary TB findings were the parameters for ITB. A new prediction scoring combining colonoscopic, laboratory, and radiologic factors increased the accuracy of diagnosis from 81.2% to 96.3% (77/80). The CD prediction score (from -2 to 2) estimated the likelihood of CD, from 0.3% for patients scoring -2 to 100% for patients scoring 2. The area under the receiver operating characteristic curve of the score was 0.990 in the development group and 0.981 in the validation group.
Conclusions: The new prediction model using a CD prediction score can be useful for calculating the probability of either CD or ITB at initial evaluation (NCT01392365).