The role of biopsies in the treatment of colitis: Scoring of disease activity

The development of new medications leads to a better disease control and clinical remission. Many clinical trials are usually needed before a new therapy can be released. The aim of clinical trials is to show efficacy and safety of the drug by defining different endpoints such as clinical and endoscopic remission and by registration of adverse events. Histology is one of the elements used in clinical trials for the assessment of the efficacy of a drug, most often as a secondary endpoint. For this purpose, scoring systems for both ulcerative colitis (UC) and Crohn's disease (CD) have been developed for the measurement of disease activity. They usually rely on a combination of histological features. While they are not designed for routine practice, the underlying concepts may be useful in daily practice as numerous recent studies have shown the power of histologic disease activity to predict relapse and long-term outcomes.