title: Full-thickness biopsy of the jejunum reveals inflammation and enteric neuropathy in irritable bowel syndrome.
abstract: OBJECTIVE
  Irritable bowel syndrome (IBS) is regarded as a functional bowel disorder. Few studies have looked for histopathologic changes in the gut and only then in biopsy specimens from intestinal mucosa. Because bowel function is governed mainly by nerve plexuses in the bowel wall, we have investigated full-thickness bowel biopsy specimens in patients with severe IBS.
  
  
  METHODS
  We used a laparoscopy-assisted technique to obtain full-thickness biopsy specimens from the proximal jejunum. Tissue specimens were investigated with light microscopy using routine stainings and immunohistochemical techniques. Horizontal sectioning was done to visualize large areas of the myenteric plexus. Fifteen autopsy specimens were used as controls regarding the myenteric plexus. Colorectal adenoma controls with terminal ileum biopsy specimens and full-thickness jejunal biopsy specimens from patients with degenerative enteric neuropathy were used as control groups for intraepithelial lymphocyte counts.
  
  
  RESULTS
  Ten patients (2 males, 8 females) were studied. In 9 patients, we found low-grade infiltration of lymphocytes in the myenteric plexus. Lymphocytes had peri- and intraganglionic location. The mean number of lymphocytes per ganglion ranged from 1.9 to 7.1 per patient, with an overall mean of 3.4. No intraganglionic lymphocytes were found in the control group and only a few periganglionic lymphocytes (mean, 0.2). Four patients had concomitant intraepithelial lymphocytosis. Neuron degeneration was evident in 6 of 9 patients with and 1 patient without ganglionic lymphocyte infiltration.
  
  
  CONCLUSIONS
  Our findings indicate that inflammation and neuronal degeneration in the myenteric plexus are involved in the pathogenesis of IBS.
authors.affiliation: Karolinska Institutet Department of Medicine, Huddinge University Hospital, Stockholm, Sweden. hans.tornblom@gastro.hs.sll.se
authors.forename: Hans
authors.initials: H
authors.lastname: Törnblom
authors.forename: Greger
authors.initials: G
authors.lastname: Lindberg
authors.forename: Björn
authors.initials: B
authors.lastname: Nyberg
authors.forename: Béla
authors.initials: B
authors.lastname: Veress
mesh_terms: D000328:Adult; D001706:Biopsy / Q000379:methods; D003109:Colonic Diseases, Functional / Q000150:complications*; D017615:Enteric Nervous System; D004751:Enteritis / Q000209:etiology* / Q000473:pathology*; D004848:Epithelium / Q000473:pathology; D005260:Female; D005724:Ganglia / Q000473:pathology; D006801:Humans; D007583:Jejunum / Q000473:pathology*; D008214:Lymphocytes / Q000473:pathology; D008297:Male; D008407:Mast Cells / Q000473:pathology; D008875:Middle Aged; D009197:Myenteric Plexus / Q000473:pathology; D009422:Nervous System Diseases / Q000209:etiology*