title: Focal-enhanced gastritis in regressive autism with features distinct from Crohn's and Helicobacter pylori gastritis.
abstract: BACKGROUND
  Immunohistochemistry allowed recent recognition of a distinct focal gastritis in Crohn's disease. Following reports of lymphocytic colitis and small bowel enteropathy in children with regressive autism, we aimed to see whether similar changes were seen in the stomach. We thus studied gastric antral biopsies in 25 affected children, in comparison to 10 with Crohn's disease, 10 with Helicobacter pylori infection, and 10 histologically normal controls. All autistic, Crohn's, and normal patients were H. pylori negative.
  
  
  METHODS
  Snap-frozen antral biopsies were stained for CD3, CD4, CD8, gammadelta T cells, HLA-DR, IgG, heparan sulphate proteoglycan, IgM, IgA, and C1q. Cell proliferation was assessed with Ki67.
  
  
  RESULTS
  Distinct patterns of gastritis were seen in the disease states: diffuse, predominantly CD4+ infiltration in H. pylori, and focal-enhanced gastritis in Crohn's disease and autism, the latter distinguished by striking dominance of CD8+ cells, together with increased intraepithelial lymphocytes in surface, foveolar and glandular epithelium. Proliferation of foveolar epithelium was similarly increased in autism, Crohn's disease and H. pylori compared to controls. A striking finding, seen only in 20/25 autistic children, was colocalized deposition of IgG and C1q on the subepithelial basement membrane and the surface epithelium.
  
  
  CONCLUSIONS
  These findings demonstrate a focal CD8-dominated gastritis in autistic children, with novel features. The lesion is distinct from the recently recognized focal gastritis of Crohn's disease, which is not CD8-dominated. As in the small intestine, there is epithelial deposition of IgG.
authors.affiliation: The Centre for Paediatric Gastroenterology, Department of Histopathology, Royal Free & University College Medical School, London.
authors.forename: Franco
authors.initials: F
authors.lastname: Torrente
authors.forename: Andrew
authors.initials: A
authors.lastname: Anthony
authors.forename: Robert B
authors.initials: RB
authors.lastname: Heuschkel
authors.forename: Michael A
authors.initials: MA
authors.lastname: Thomson
authors.forename: Paul
authors.initials: P
authors.lastname: Ashwood
authors.forename: Simon H
authors.initials: SH
authors.lastname: Murch
mesh_terms: D001321:Autistic Disorder / Q000150:complications*; D001706:Biopsy; D002648:Child; D003424:Crohn Disease / Q000150:complications* / Q000473:pathology*; D005260:Female; D005756:Gastritis / Q000150:complications* / Q000473:pathology*; D016481:Helicobacter Infections / Q000150:complications* / Q000473:pathology*; D016480:Helicobacter pylori; D006801:Humans; D007150:Immunohistochemistry; D008297:Male