title: Reduced hydrophobicity of the colonic mucosal surface in ulcerative colitis as a hint at a physicochemical barrier defect.
abstract: OBJECTIVE
  There is increasing evidence that a defect of the gastrointestinal mucosal barrier is important for the development of inflammatory bowel diseases (IBD). The hydrophobicity of the colonic mucosal surface is a measure of its resistance to luminal antigens, e.g. of bacterial origin. Therefore, the purpose of this study was to determine this parameter in patients suffering from IBD.
  
  
  METHODS
  Nineteen patients with ulcerative colitis (UC), ten patients with Crohn's disease (CD) and 20 controls were examined. All underwent colonic surgery at the University Hospital Heidelberg. Clinical disease activity was determined. From every subject, colonic tissue specimens were obtained, and hydrophobicity of the mucosal surface was determined with a goniometer by multiple plateau contact angle measurements. Histological evaluation of disease activity was performed in directly adjacent tissue specimens.
  
  
  RESULTS
  Hydrophobicity of the colonic mucosal surface, expressed as plateau contact angles, was significantly reduced in patients with UC (mean ± SEM, 47.8° ± 3.4°) compared to those with CD (72.0° ± 5.2°) and controls (72.5° ± 5.6°; over-all P = 0.0004; UC versus controls, P < 0.001; UC versus CD, P < 0.05; CD versus controls, P > 0.05). Between mucosal hydrophobicity and clinical disease activity, as well as mucosal hydrophobicity and histological disease activity, no significant correlation was found.
  
  
  CONCLUSIONS
  The results suggest a defective physicochemical barrier as an essential factor in the pathogenesis of UC, but not CD. The fact that no correlation was found between mucosal hydrophobicity and disease activity may indicate that the loss of mucosal hydrophobicity in UC is not exclusively a secondary effect due to inflammation.
authors: Department of Gastroenterology, University Hospital Heidelberg, INF 410, 69120, Heidelberg, Germany.
authors: Annika
authors: A
authors: Braun
authors: Ulrike
authors: U
authors: Schönfeld
authors: Thilo
authors: T
authors: Welsch
authors: Martina
authors: M
authors: Kadmon
authors: Benjamin
authors: B
authors: Funke
authors: Daniel
authors: D
authors: Gotthardt
authors: Alexandra
authors: A
authors: Zahn
authors: Frank
authors: F
authors: Autschbach
authors: Peter
authors: P
authors: Kienle
authors: Michael
authors: M
authors: Zharnikov
authors: Michael
authors: M
authors: Grunze
authors: Wolfgang
authors: W
authors: Stremmel
authors: Robert
authors: R
authors: Ehehalt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000473:pathology*; D003106:Colon / Q000473:pathology*; D003424:Crohn Disease / Q000473:pathology; D005260:Female; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007413:Intestinal Mucosa / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D013499:Surface Properties; D055815:Young Adult