Relationships between Helicobacter pylori infection status, endoscopic, histopathological findings, and cytokine production in the duodenum of Crohn's disease patients

Background: The chronic inflammatory process in patients with Crohn's disease (CD) may affect any part of the gastrointestinal (GI) tract. The pathogenesis of CD involves immunological abnormalities, including deficient or excessive expression of cytokines. We examined Helicobacter pylori infection status, endoscopic and histopathological findings, and cytokine production in the duodenum of CD patients in comparison with controls. Methods: Thirty-eight CD patients underwent diagnostic upper GI endoscopy. Twelve age- and sex-matched health checkup examinees were used as controls. H. pylori infection status was assessed by the ¹³C-urea breath test. At the time of endoscopy, two biopsy specimens each were obtained from the second portion of the duodenum, one for hematoxylin-eosin staining and immunohistochemical analysis with anti-CD68 antibody, and one for in vitro organ culture. Interleukin (IL)-6 and -8 levels were measured in organ culture supernatant by enzyme-linked immunosorbent assay. Results: H. pylori infection was significantly (P < 0.05) more frequent in controls (42%) than in CD patients (8%). In the duodenum, erosions or ulcers were more frequent in CD patients (53%) than in controls (8%). Mononuclear cell infiltration in the duodenum was more severe in CD patients than in controls and IL-6 production was higher, whereas IL-8 production showed no significant difference. CD68+ cells in the duodenum were more prominent in CD patients than in controls. Conclusions: H. pylori infection is unlikely in CD patients, but they show immunological abnormalities in the duodenum, possibly from innate immune responses.