Background: Intestinal permeability and altered inflammatory responses, along with genetic and environmental factors, likely contribute to the pathogenesis of Crohn's disease.
Aims: This study aimed to assess the presence and prevalence of subclinical intestinal inflammation among apparently healthy, first-degree relatives of pediatric patients with Crohn's disease, using non-invasive fecal markers.
Methods: Stool samples were collected from 13 patients with Crohn's disease, 36 siblings and 41 parents. S100A12 levels were measured using an in-house ELISA assay and calprotectin levels were determined using the PhiCal test, with levels compared to normal healthy population controls.
Results: Fecal S100A12 levels in siblings (median, 14 mg/kg; 95% confidence interval [CI], 9-32 mg/kg) and patients (71 mg/kg; CI 4-286 mg/kg) differed significantly from pediatric controls (1 mg/kg; CI 1-5 mg/kg; p < 0.001). In contrast, fecal calprotectin levels in siblings (22 mg/kg; CI 15-31 mg/kg) were lower than that of pediatric controls (31 mg/kg; CI 19-52 mg/kg; p = 0.03). Fecal markers were not elevated in parents compared to adult controls.
Conclusions: This study provides further evidence of subclinical intestinal inflammation amongst first-degree relatives of patients with Crohn's disease. The presence of sub-clinical gut inflammation may be a risk factor for the subsequent development of Crohn's disease.