Elevated basal intestinal mucosal cytokine levels in asymptomatic first-degree relatives of patients with Crohn's disease

Aim: To determine levels of cytokines in colonic mucosa of asymptomatic first degree relatives of Crohn's disease patients. Methods: Cytokines (Interleukin (IL) 1-Beta, IL-2, IL-6 and IL-8) were measured using ELISA in biopsy samples of normal looking colonic mucosa of first degree relatives of Crohn's disease patients (n = 9) and from normal controls (n = 10) with no family history of Crohn's disease. Results: Asymptomatic first degree relatives of patients with Crohn's disease had significantly higher levels of basal intestinal mucosal cytokines (IL-2, IL-6 and IL-8) than normal controls. Whether these increased cytokine levels serve as phenotypic markers for a genetic predisposition to developing Crohn's disease later on, or whether they indicate early (pre-clinical) damage has yet to be further defined. Conclusion: Asymptomatic first degree relatives of Crohn's disease patients have higher levels of cytokines in their normal-looking intestinal mucosa compared to normal controls. This supports the hypothesis that increased cytokines may be a cause or an early event in the inflammatory cascade of Crohn's disease and are not merely a result of the inflammatory process.