Chronic use of non-steroidal anti-inflammatory drugs does not alter colonic mucosa of patients without diarrhoea

Abstract

Background: Several types of colitis can be NSAID-induced, but whether chronic use of NSAIDs alters colonic mucosa in patients without diarrhoea is not known. Patients and methods: Biopsy specimens of rectal mucosa were taken in six patients with rheumatoid arthritis without diarrhoea receiving NSAIDs (group 1, n = 6). Patients with rheumatoid arthritis without diarrhoea not receiving NSAIDs (group 2, n = 9), and patients undergoing surveillance colonoscopy (group 3, n = 23) served as controls. In all patients from the three study groups, intraepithelial lymphocyte count and apoptotic cell count were assessed, and sub-epithelial collagen band thickness was measured. Leucocyte population of lamina propria was evaluated semi-quantitatively. HLA-DR and CD25 expression of mucosal cells was appreciated by immunohistochemistry. Results: Intraepithelial lymphocyte count was in the normal range in all three group patients, and not statistically different between groups. Apoptotic epithelial cell count was not different between groups. Sub-epithelial collagen band thickness was normal in all the patients. No patient had a marked infiltration of lamina propria by leucocytes, and HLA-DR and CD25 were normally expressed in all patients. Conclusion: These results from a small sample of patients suggest that patients without diarrhoea receiving NSAIDs on a long-term basis do not develop microscopic or inflammatory colitis.