title: Serum and colonic mucosal immune markers in irritable bowel syndrome.
abstract: OBJECTIVE
  Low-grade colonic mucosal inflammation has been postulated to have an important role in the pathophysiology of irritable bowel syndrome (IBS). The objectives of this study were (i) to identify serum and tissue-based immunological and neuroendocrine markers associated with mucosal inflammation in male (M) and female (F) patients with non-post-infectious IBS (non-PI-IBS) compared with healthy controls and (ii) to assess possible correlations of such markers with IBS symptoms.
  
  
  METHODS
  Sigmoid mucosal biopsies were obtained from 45 Rome II positive IBS patients without a history of PI-IBS (26 F, 35.5% IBS-C, 33.3% IBS-D, 31.1% IBS-A/M) and 41 healthy controls (22 F) in order to measure immunological markers (serum cytokine levels, colonic mucosal mRNA levels of cytokines, mucosal immune cell counts) and neuroendocrine markers associated with mucosal inflammation (corticotropin releasing factor- and neurokinin (NK)-related ligands and receptors, enterochromaffin cells). Symptoms were measured using validated questionnaires.
  
  
  RESULTS
  Of all the serum and mucosal cytokines measured, only interleukin-10 (IL-10) mRNA expression showed a group difference, with female, but not male, patients showing lower levels compared with female controls (18.0±2.9 vs. 29.5±4.0, P=0.006). Mucosal mRNA expression of NK-1 receptor was significantly lower (1.15±0.19 vs. 2.66±0.56, P=0.008) in female, but not male, patients compared with healthy controls. No other significant differences were observed.
  
  
  CONCLUSIONS
  Immune cell counts and levels of cytokines and neuropeptides that are associated with inflammation were not significantly elevated in the colonic mucosa of non-PI-IBS patients, and did not correlate with symptoms. Thus, these findings do not support that colonic mucosal inflammation consistently has a primary role in these patients. However, the finding of decreased IL-10 mRNA expression may be a possible biomarker of IBS and warrants further investigation.
authors.affiliation: Center for Neurobiology of Stress, University of California, Los Angeles, California 90095-7378, USA. linchang@ucla.edu
authors.forename: Lin
authors.initials: L
authors.lastname: Chang
authors.forename: Mopelola
authors.initials: M
authors.lastname: Adeyemo
authors.forename: Iordanis
authors.initials: I
authors.lastname: Karagiannides
authors.forename: Iordanis
authors.initials: I
authors.lastname: Karagiannidis
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Videlock
authors.forename: Collin
authors.initials: C
authors.lastname: Bowe
authors.forename: Wendy
authors.initials: W
authors.lastname: Shih
authors.forename: Angela P
authors.initials: AP
authors.lastname: Presson
authors.forename: Pu-Qing
authors.initials: PQ
authors.lastname: Yuan
authors.forename: Galen
authors.initials: G
authors.lastname: Cortina
authors.forename: Hua
authors.initials: H
authors.lastname: Gong
authors.forename: Sharat
authors.initials: S
authors.lastname: Singh
authors.forename: Arlene
authors.initials: A
authors.lastname: Licudine
authors.forename: Minou
authors.initials: M
authors.lastname: Mayer
authors.forename: Yvette
authors.initials: Y
authors.lastname: Tache
authors.forename: Charalabos
authors.initials: C
authors.lastname: Pothoulakis
authors.forename: Emeran A
authors.initials: EA
authors.lastname: Mayer
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000378:metabolism*; D003106:Colon / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D007413:Intestinal Mucosa / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D043183:Irritable Bowel Syndrome / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D018040:Receptors, Neurokinin-1 / Q000378:metabolism; D012737:Sex Factors; D011795:Surveys and Questionnaires
chemical_list: D015415:Biomarkers; D016207:Cytokines; D018040:Receptors, Neurokinin-1; D016753:Interleukin-10