Successful Eradication of Helicobacter pylori Could Prevent Metachronous Gastric Cancer: A Propensity Matching Analysis.

BACKGROUND AND AIM: Helicobacter pylori is the leading cause of gastric cancer, but it is still uncertain whether eradicating H. pylori in early gastric cancer (EGC) patients who underwent endoscopic resection can prevent metachronous gastric cancer (MGC). This study aimed to investigate the effect of H. pylori eradication to prevent MGC after endoscopic submucosal dissection (ESD). METHODS: In this propensity-matched retrospective observational study, 770 patients with EGC who received ESD were enrolled. The outcome was the incidence of MGC; this was compared between the persistent and eradicated groups. RESULTS: MGC was detected in 27 patients (7.8%) during a median period of 39.0 months (range 26.0-64.0). After propensity matching, 126 pairs of patients in each group were analyzed. The 5-year cumulative incidence rates of MGC were 13.2 and 3.9% in the persistent and eradicated groups, respectively (p= 0.021, log-rank test). On multivariate analysis, H. pylori eradication prevented MGC significantly (hazard ratio [HR] 0.32; p = 0.029). The results remained robust after inverse probability of treatment weighting analysis (HR 0.30; p = 0.020). CONCLUSIONS: Successful H. pylori eradication could prevent MGC after ESD for EGC.

Intestinal epithelial cell endoplasmic reticulum stress promotes MULT1 up-regulation and NKG2D-mediated inflammation.

Endoplasmic reticulum (ER) stress is commonly observed in intestinal epithelial cells (IECs) and can, if excessive, cause spontaneous intestinal inflammation as shown by mice with IEC-specific deletion of X-box-binding protein 1 (Xbp1), an unfolded protein response-related transcription factor. In this study, Xbp1 deletion in the epithelium (Xbp1ΔIEC ) is shown to cause increased expression of natural killer group 2 member D (NKG2D) ligand (NKG2DL) mouse UL16-binding protein (ULBP)-like transcript 1 and its human orthologue cytomegalovirus ULBP via ER stress-related transcription factor C/EBP homology protein. Increased NKG2DL expression on mouse IECs is associated with increased numbers of intraepithelial NKG2D-expressing group 1 innate lymphoid cells (ILCs; NK cells or ILC1). Blockade of NKG2D suppresses cytolysis against ER-stressed epithelial cells in vitro and spontaneous enteritis in vivo. Pharmacological depletion of NK1.1+ cells also significantly improved enteritis, whereas enteritis was not ameliorated in Recombinase activating gene 1-/-;Xbp1ΔIEC mice. These experiments reveal innate immune sensing of ER stress in IECs as an important mechanism of intestinal inflammation.

Dislocation of Rab13 and vasodilator-stimulated phosphoprotein in inactive colon epithelium in patients with Crohn's disease.

Crohn's disease is associated with increased permeability of the intestine even in quiescent patients. Increased intestinal permeability may cause dysregulated immunological responses in the intestinal mucosa that leads to chronic intestinal inflammation. Tight junction proteins contribute to intestinal permeability, and functional abnormality and dislocation of such proteins may cause increased intestinal permeability. We studied the expression of tight junction proteins Rab13, vasodilator-stimulated phosphoprotein (VASP), zonula occludin-1 (ZO-1), and F-actin in the intestinal epithelium of patients with inactive inflammatory bowel disease. Surgical samples were obtained from 10 controls (without inflammatory bowel disease), 10 patients with Crohn's disease and 7 patients with ulcerative colitis. F-actin was visualized with fluorescent phalloidin. Tight junction proteins were visualized by an immunofluorescence method. Rab13, VASP, and ZO-1 were found in apical tight junctions in normal epithelium but were dislocated to the basolateral position in patients with inactive Crohn's disease, whereas the structure of F-actin was maintained in inactive mucosa. In patients with ulcerative colitis, these tight junction proteins were not dislocated. Latent dislocation of tight junction proteins in the inactive mucosa of patients with Crohn's disease may permit the invasion of gut antigens to initiate and perpetuate altered immune response.