Background & aims: Presence of a familial intestinal permeability defect in Crohn's disease remains controversial despite numerous studies. The purpose of this study was to determine whether detection of a permeability defect in first-degree relatives of patients with Crohn's disease can be enhanced using an acetylsalicylic acid provocation test.
Methods: Lactulose-mannitol ratio, a measure of intestinal permeability, and total sucrose excretion, a measure of gastroduodenal permeability, were determined before and after ingestion of acetylsalicylic acid in healthy controls, in patients with Crohn's disease, and in the first-degree relatives of patients with Crohn's disease. Subjects were classified as hyperresponders if their results were above the mean of + 2SD of the controls.
Results: First-degree relatives had a 110% increase in intestinal permeability after acetylsalicylic acid compared with an increase of 57% in controls (P = 0.001). Thirty-five percent of relatives were classified as hyperresponders. There was no significant difference in the change in sucrose excretion between relatives and controls (259% vs 198%; P < 0.05).
Conclusions: First-degree relatives of patients with Crohn's disease have an exaggerated increase in intestinal but not gastroduodenal permeability in response to acetylsalicylic acid. This study supports a familial permeability defect in Crohn's disease, which may not be present in all families.