Frequency of continuing mucosal inflammation in clinically inactive Crohn's disease

The treatment goal in Crohns disease is clinical remission, not complete mucosal healing. The incidence of mucosal inflammation in Crohns disease patients in clinical remission is not known. Whole gut lavage is an objective method of assessing mucosal inflammation. We aimed to assess levels of mucosal inflammatory activity in a group of patients with clinically inactive Crohns disease. We prospectively assessed 30 patients with inactive Crohn disease and 28 controls. Inactive disease was defined as Crohns disease activity index of less than 150. All underwent whole put lavage, with analysis of whole gut lavage fluid IgG, haemoglobin, interleukin-1 beta interleukin-8 and granulocyte elastase. Serum inflammatory parameters were collected for comparison. Of the 30 patients with Crohns disease, 10 (33%) had an abnormal immunoglobulin G, 21 (70%) had an elevated interleukin-Ig 20 (66%,) interleukin-8 and 10 (33%) granulocyte elastase in the whole gut lavage fluid. 58% of patients had either 1 or 2 abnormal results. In contrast only 10% had 1 or 2 abnormal serum results. Few abnormalities were present in lavage fluid or serum of the control population. We concluded that ongoing mucosal inflammation is detectable in whole gut lavage fluid of up to 2/3 of Crohns disease patients in clinical remission.