title: Early changes in rectal nitric oxide and mucosal inflammatory mediators in Crohn's colitis in response to infliximab treatment.
abstract: BACKGROUND
  Treatment with tumor necrosis factor-alpha monoclonal antibody (infliximab) reduces clinical activity and intestinal inflammation in Crohn's disease.
  
  
  OBJECTIVE
  To study the time-course of the effects of infliximab with reference to mucosal cytokine and inducible nitric oxide synthase expression.
  
  
  METHODS
  Thirty-two patients with Crohn's disease were treated with single dose infliximab (5 mg/kg). Disease activity was assessed days 1, 3, 7 and 28 using Harvey-Bradshaw index. Rectal nitric oxide levels were determined and rectal biopsies collected before treatment, 1 h after infusion and on days 3, 7 and 28. Immunohistochemical staining against inducible nitric oxide synthase, tumor necrosis factor-alpha, interleukin-1beta and interferon-gamma were performed.
  
  
  RESULTS
  Clinical response was seen in 14 patients with down-regulation of global immunohistochemistry expression, reaching nadir day 3. Rectal nitric oxide was increased at baseline (3578 +/- 1199 parts per billion, ppb) compared with controls (89 +/- 13 ppb) (P < 0.001). In patients with clinical response, rectal nitric oxide decreased from 3926 +/- 1687 ppb to 1050 +/- 428 ppb day 28 (P < 0.05).
  
  
  CONCLUSIONS
  Down-regulation of mucosal inflammatory mediators occurs after infliximab. Rectal nitric oxide levels parallel down-regulation of inducible nitric oxide synthase, tumor necrosis factor-alpha, interleukin-1beta and interferon-gamma and may serve as a quantitative biomarker of intestinal inflammation.
authors.affiliation: Department of Gastroenterology and Hepatology, Karolinska University Hospital, Stockholm, Sweden. Per.Hellstrom@ki.se
authors.forename: T
authors.initials: T
authors.lastname: Ljung
authors.forename: L-G
authors.initials: LG
authors.lastname: Axelsson
authors.forename: M
authors.initials: M
authors.lastname: Herulf
authors.forename: J O
authors.initials: JO
authors.lastname: Lundberg
authors.forename: P M
authors.initials: PM
authors.lastname: Hellström
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D003424:Crohn Disease / Q000188:drug therapy* / Q000473:pathology; D016207:Cytokines / Q000378:metabolism; D005260:Female; D005765:Gastrointestinal Agents / Q000627:therapeutic use*; D006801:Humans; D000069285:Infliximab; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D012007:Rectum / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D016207:Cytokines; D005765:Gastrointestinal Agents; D000069285:Infliximab; D052247:Nitric Oxide Synthase Type II