Abnormal Intestinal Permeability Predicts Relapse in Inactive Crohn Disease

BACKGROUND: Trials of maintenance therapy in quiescent Crohn disease are often underpowered and there is need for objective markers that predict relapse. Intestinal permeability (IP) has been identified as such a marker although it is unknown how this relates to proposed clinical and blood markers of relapse. We aimed to assess the predictive value of intestinal permeability together with clinical and blood markers in a group of patients with inactive Crohn disease. METHODS: We assessed 50 patients with inactive Crohn disease. Inactive disease was defined as a Crohn disease activity index of less than 150. Intestinal permeability was measured by the urinary excretion of lactulose and rhamnose and data relating to postulated clinical and blood markers predictive of relapse were collected. Follow-up for one year assessed whether patients had relapsed or remained in remission. RESULTS: Of the 18 patients with abnormal intestinal permeability, 10 remained in remission and 8 relapsed. Of the 32 with a normal result, 31 remained in remission and 1 relapsed. Patients with abnormal intestinal permeability are significantly more likely to relapse than those with a normal result (chi-square = 14.3; P = 0.0001; relative risk 18). Those that relapsed had shorter disease duration. Multiple regression analysis identifies IP to be an independent variable. CONCLUSIONS: Abnormal intestinal permeability in patients with inactive Crohn disease predicts relapse. This is superior to clinical and blood markers. It is likely that this is due to ongoing subclinical mucosal inflammation. This may be of use when designing clinical trials of maintenance therapy.