title: The mechanisms of prednisone inhibition of inflammation in Crohn's disease involve changes in intestinal permeability, mucosal TNFalpha production and nuclear factor kappa B expression.
abstract: BACKGROUND
  The clinical course of Crohn's disease after the induction of remission with medical therapy is characterized by unpredictable relapse.
  
  
  OBJECTIVE
  To evaluate three surrogate markers, intestinal permeability, mucosal TNFalpha and nuclear factor (NF)-kappaB/IkappaBalpha expression, in order to determine the relationship of these parameters to clinical relapse.
  
  
  METHODS
  Thirty patients with active Crohn's disease were treated with a 10 week course of prednisone using a tapering dosing regimen. Intestinal permeability (lactulose/mannitol [L/M ratio]) was determined at baseline and at the end of prednisone tapering. TNFalpha production and the levels of expression of NF-kappaB/IkappaBalpha were measured in colonic mucosal biopsies obtained after the induction of remission.
  
  
  RESULTS
  Twenty-two patients (73%) achieved remission and 50% of patients experienced a clinical relapse during the ensuing 12 months. Treatment with prednisone resulted in a significant decrease in the L/M ratio. Of the patients that relapsed, 75% had a raised L/M ratio at the time of remission compared with 20% of patients with a normal L/M ratio (P < 0.008; hazard ratio = 6.094; CI 1.55, 17.43). Mucosal TNFalpha production was greater in relapsers compared with those who remained in remission. The levels of NF-kappaB in relapsers were significantly greater and levels of cytosolic IkappaBalpha were significantly lower compared with those measured in patients who remained in remission.
  
  
  CONCLUSIONS
  These findings underscore the importance of incorporating biological parameters of inflammation in determining the clinical course of Crohn's disease.
authors.affiliation: Department of Medicine, Division of Gastroenterology, McGill University, Montreal, Canada. gary.wild@muhc.mcgill.ca
authors.forename: G E
authors.initials: GE
authors.lastname: Wild
authors.forename: K A
authors.initials: KA
authors.lastname: Waschke
authors.forename: A
authors.initials: A
authors.lastname: Bitton
authors.forename: A B R
authors.initials: AB
authors.lastname: Thomson
mesh_terms: D000328:Adult; D015153:Blotting, Western; D003424:Crohn Disease / Q000188:drug therapy*; D005260:Female; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000378:metabolism*; D010539:Permeability / Q000187:drug effects; D011241:Prednisone / Q000494:pharmacology / Q000627:therapeutic use*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D020672:I-kappa B Proteins; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D011241:Prednisone