Select a suitable treatment strategy for Crohn's disease: step-up or top-down.

Crohn's Disease (CD) is a chronic immune-mediated disorder with progressive and destructive course. Current guidelines on the treatment strategy still recommend a step-up approach with sequential prescription of corticosteroids and immunosuppressives. However, mounting evidences manifested that top-down therapy with early administration of anti-TNF or combination of immunosuppressives can achieve more rapid and higher rate of mucosal healing and has the potential of modifying the natural course of disease. Therefore, who is suitable to accept and when to start anti-TNF therapy have attracted the attention of gastroenterologists. And what benefit/risk can be expected from the two strategies should be carefully taken into account by clinicians. Age stratification, special patients, disease location and extension, genetic and serologic testing are predictors of disease progression and complication and thus guide a personalized treatment approach in CD. A definition of early CD has been proposed to select an algorithm for treatment of moderate-to-severe CD with a suitable strategy. To date mucosal healing has been widely used, the Lémann score, which assesses the extent and severity of bowel damage at a specific time-point and over time, and is a new disability index for patients with CD, will be considered as a new endpoint for future studies of treatment strategies. Besides medicines of the two strategies, surgery, vaccine, Leukocytapheresis and stem cell therapy are all effective therapeutic approaches which lead to another thinking about what should they be putted in the conditional pyramid. However, we are trying to answer these questions.