title: Systemic and local cytokine production in quiescent ulcerative colitis and its relationship to future relapse: a prospective pilot study.
abstract: BACKGROUND
  The main aim of this prospective study was to examine whether systemic (plasma) and local (mucosal) cytokine production is a predictor of future relapse in patients with quiescent ulcerative colitis (UC). The impact of other clinical and laboratory parameters on relapse was also studied.
  
  
  METHODS
  Fifty consecutive patients with quiescent UC were included. At enrollment, blood and mucosal (rectal biopsies) samples were collected. All patients were followed up regularly for 1 year after enrollment. Plasma and mucosal cytokine levels were measured by enzyme-linked immunosorbent assay. To identify independent significant predictive factors for relapse, time-dependent analyses using the Kaplan-Meier method and the Cox proportional hazard model were performed.
  
  
  RESULTS
  Thirty-four patients remained in remission, and 16 patients relapsed during the 1-year follow-up. Higher interleukin (IL)-8 levels in the rectal mucosa were significantly associated with relapse. In contrast, IL-1beta, IL-6, and tumor necrosis factor-alpha levels in the rectal mucosa were not associated with relapse. Conventional blood markers and plasma cytokines (IL-1beta, IL-6, IL-8, and tumor necrosis factor-alpha) did not correlate with relapse. Among clinical factors, age and number of prior relapses were significantly associated with relapse. In multivariate analysis, a higher rectal mucosal IL-8 level (> or = 160 pg/mg of tissue; hazard ratio, 4.7), younger age (<30 yr; hazard ratio, 7.3), and a greater number of prior relapses (> or = 5; hazard ratio, 4.3) were independent significant risk factors for future relapse.
  
  
  CONCLUSIONS
  Rectal mucosal IL-8 measurement might be an additional objective diagnostic tool that can predict relapse in patients with quiescent UC.
authors.affiliation: Inflammatory Bowel Disease Center, Yokkaichi Social Insurance Hospital, Yokkaichi, Mie, Japan. nao-taka@sannet.ne.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Satoru
authors.initials: S
authors.lastname: Umegae
authors.forename: Tatsushi
authors.initials: T
authors.lastname: Kitagawa
authors.forename: Koichi
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D000328:Adult; D000367:Age Factors; D001706:Biopsy; D003093:Colitis, Ulcerative / Q000276:immunology* / Q000473:pathology*; D016207:Cytokines / Q000032:analysis / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D012007:Rectum / Q000166:cytology / Q000276:immunology; D012008:Recurrence; D012307:Risk Factors
chemical_list: D016207:Cytokines