Increased rectal nitric oxide in coeliac disease after local challenge with gluten

Background: Coeliac disease is an inflammatory disorder characterized by reversible atrophy of small intestinal villi following the ingestion of gluten. Earlier studies indicate that the inflammatory response to gluten may occur also very distally in the gastrointestinal tract. The aim of this study was to evaluate whether rectal challenge with gluten would trigger an increased local production of the gas nitric oxide (NO), a novel marker of intestinal inflammation. Methods: Rectal challenge with partially digested gluten was performed in 20 patients with treated coeliac disease and in 13 healthy controls. Luminal levels of NO were measured in the rectum at 0, 8 and 24 h using a chemiluminescence technique. Results: In patients with coeliac disease mean rectal NO increased from 235 +/- 90 parts per billion (ppb) at 0 h to 4965 +/- 1653 ppb at 24 h (P < 0.005). In the control group there was no significant increase. One control subject responded with high NO levels at 24 h and the same individual tested positive for anti-endomysium IgA antibodies. Subsequent duodenal biopsing showed substantial villusatrophy. Conclusions: Rectal challenge with gluten results in increased luminal levels of NO in a group of patients with treated coeliac disease. Further studies are needed to evaluate the role of NO in coeliac disease and the potential usefulness of rectal NO measurements in aiding diagnosis of this intestinal disorder.