A prospective study into the aetiology of lymphocytic duodenosis

P>Background Lymphocytic duodenosis is defined by normal villous architecture and intraepithelial lymphocytes (IELs) > 25 per 100 enterocytes. Such patients should not be diagnosed with coeliac disease, solely by histology, as previous retrospective studies have suggested other associations with lymphocytic duodenosis. Aim To study prospectively the aetiology of lymphocytic duodenosis. Methods One hundred patients with lymphocytic duodenosis were investigated rigorously for coeliac disease and other known associations for lymphocytic duodenosis by initial investigations of coeliac serology, and exclusion of infection. Of 34 with no explanation for lymphocytic duodenosis, 29 underwent repeat duodenal biopsies following a gluten challenge. Results Coeliac disease was present in 16% of patients with lymphocytic duodenosis. In the absence of a positive coeliac diagnosis, lymphocytic duodenosis was most commonly associated with drugs (21%), infection (19%), immune dysregulation (4%), inflammatory bowel disease (2%), microscopic colitis (2%), sarcoidosis (1%) and IgA deficiency (1%). Of 34 with no known associations, 18 had symptoms of irritable bowel syndrome (IBS), and in 29 patients investigated with repeat duodenal biopsies, the IEL count returned to normal in 22. Conclusions In 66% of cases of lymphocytic duodenosis, a known association can be found by further investigations; importantly, 16% will have coeliac disease. In those with no apparent cause, there may be an association with IBS and the IEL count becomes normal on repeat biopsy in 76%.