Prediction of treatment refractoriness in ulcerative colitis and Crohn's disease--do we have reliable markers?

Treatment refractoriness is a severe problem in the management of patients with ulcerative colitis and Crohn's disease. Despite some promising new therapeutic approaches, corticosteroids are still the preferential primary treatment for moderate to severe Crohn's disease and of severe ulcerative colitis. However, clinical response to corticosteroids varies, and many patients are resistant to such treatment. Since corticosteroids have frequent and even severe side effects, and toxicity increases with chronic steroid intake, factors predictive of response to such treatment would be very helpful for decisions on further management of these patients. At least in severe attacks of ulcerative colitis, the consensus seems to be that a high frequency of bowel movements as well as a high C-reactive protein and low serum albumin recorded after a few days of intensive medical treatment are important signs for early prediction of treatment failure in the majority of the patients. In Crohn's disease thus far, data on predictive factors are conflicting. No reliable marker with sufficient predictive value for treatment refractoriness could be identified. This might be due to the tremendous heterogeneity of Crohn's disease with many clinical phenotypes, which requires subgroup analysis with sufficient numbers of patients. Corticosteroids as well as other immunomodulating and immunosuppressive medications interfere with the immune system, which plays a central role in the mediation of intestinal inflammation. Treatment refractoriness might have its origin in specific immunological peculiarities eventually reflected in abnormal immunological, biochemical, and clinical parameters. Further exploration of those parameters to predict treatment refractoriness in patients with ulcerative colitis or Crohn's disease is of great clinical importance for safe and efficient management of patients.