Clinical predictors of Crohn's disease course.

A modern approach to Crohn's disease (CD) should be influenced by the patient's underlying prognosis. Here, I analyse the clinical factors predicting CD course on the basis of information obtained at diagnosis and in the year following diagnosis. Perianal disease at diagnosis appears to be a strong predictor of unfavourable outcome and has been associated with a more frequent use of immunosuppressive treatment. Early age at diagnosis, ileocolonic disease and extraintestinal manifestations are characteristics of patients at risk for more complicated disease. Otherwise, patients subjected to surgery at diagnosis or during the first year of follow-up appear to have a relatively benign outcome. Disease activity in the year after diagnosis appears to be a good predictor of future disease activity as about two-third of the patients who remain in remission tend to remain unchanged thereafter, whereas those patients treated with steroids have, manifestly, an unfavourable subsequent clinical course. Moreover, there is consistent evidence that active smoking is associated with a complicated disease course. The results of the studies reviewed suggest that the combination of 'phenotype at diagnosis' and 'comportment follow-up classification' in the year following diagnosis can be potentially useful prognostic factors in clinical practice. With the development of newer therapies in CD, there is a growing need to predict disease outcome, despite the difficult challenge in anticipating the future clinical course in a given patient.