title: Microscopic colitis patients demonstrate a mixed Th17/Tc17 and Th1/Tc1 mucosal cytokine profile.
abstract: BACKGROUND
  Microscopic colitis (MC) is a chronic inflammatory bowel disorder of unknown aetiology comprising collagenous colitis (CC) and lymphocytic colitis (LC). Data on the local cytokine profile in MC is limited. This study investigated the T helper (Th) cell and cytotoxic T lymphocyte (CTL) mucosal cytokine profile at messenger and protein levels in MC patients.
  
  
  METHODS
  Mucosal biopsies from CC (n=10), LC (n=5), and CC or LC patients in histopathological remission (CC-HR, n=4), (LC-HR, n=6), ulcerative colitis (UC, n=3) and controls (n=10) were analysed by real-time PCR and Luminex for expression/production of IL-1β, -4, -5, -6, -10, -12, -17, -21, -22, -23, IFN-γ, TNF-α, T-bet and RORC2.
  
  
  RESULTS
  Mucosal mRNA but not protein levels of IFN-γ and IL-12 were significantly up regulated in CC, LC as well as UC patients compared to controls. Transcription of the Th1 transcription factor T-bet was significantly enhanced in CC but not LC patients. mRNA levels for IL-17A, IL-21, IL-22 and IL-6 were significantly up regulated in CC and LC patients compared to controls, albeit less than in UC patients. Significantly enhanced IL-21 protein levels were noted in both CC and LC patients. IL-6 protein and IL-1β mRNA levels were increased in CC and UC but not LC patients. Increased mucosal mRNA levels of IFN-γ, IL-21 and IL-22 were correlated with higher clinical activity, recorded as the number of bowel movements per day, in MC patients. Although at lower magnitude, IL-23A mRNA was upregulated in CC and LC, whereas TNF-α protein was increased in CC, LC as well as in UC patients. Neither mRNA nor protein levels of IL-4, IL-5 or IL-10 were significantly changed in any of the colitis groups. LC-HR and especially CC-HR patients had normalized mRNA and protein levels of the above cytokines compared to LC and CC patients. No significant differences were found between LC and CC in cytokine expression/production.
  
  
  CONCLUSIONS
  LC and CC patients demonstrate a mixed Th17/Tc17 and Th1/Tc1 mucosal cytokine profile.
authors.affiliation: School of Health and Medical Sciences, Örebro University, Sweden. ashok.kumawat@oru.se
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Kumawat
authors.forename: Hilja
authors.initials: H
authors.lastname: Strid
authors.forename: Curt
authors.initials: C
authors.lastname: Tysk
authors.forename: Johan
authors.initials: J
authors.lastname: Bohr
authors.forename: Elisabeth Hultgren
authors.initials: EH
authors.lastname: Hörnquist
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D046729:Colitis, Collagenous / Q000235:genetics / Q000276:immunology / Q000473:pathology; D046730:Colitis, Lymphocytic / Q000235:genetics / Q000276:immunology / Q000473:pathology; D046728:Colitis, Microscopic / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D006801:Humans; D018928:Immunity, Mucosal / Q000235:genetics; D008297:Male; D008875:Middle Aged; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000473:pathology; D018417:Th1 Cells / Q000276:immunology* / Q000473:pathology; D058504:Th17 Cells / Q000276:immunology* / Q000473:pathology; D055815:Young Adult
chemical_list: D016207:Cytokines