See my emphasis below in bold.
Hmmmmm... ;)Microscopic colitis demonstrates a TH1 mucosal cytokine profile.Tagkalidis PP, Gibson P, Bhathal PS.
Royal Melbourne Hospital, Australia.
Background and aims: Microscopic colitis is an inflammatory disorder of unknown etiology. The aim was to characterize the mucosal cytokine profile of microscopic colitis with a view to understanding its potential pathogenic mechanisms. METHODS: Mucosal biopsies taken at flexible sigmoidoscopy from 18 patients (8 lymphocytic colitis and 10 collagenous colitis) were analyzed for cytokine profile using real time RT-PCR, in comparison to those from 13 aged-matched controls with diarrhoea-predominant irritable bowel syndrome. Biopsies from 6 patients with histologically documented remission were available for comparative analysis. Biopsies were also taken to determine the cellular expression of cytokine and cytokine-related proteins using immunohistochemistry. RESULTS: Mucosal mRNA levels were 100 times greater for interferon-gamma and interleukin-15, 60 times greater for tumor necrosis factor-alpha, and 35 times greater for inducible nitric oxide synthase in microscopic colitis compared to controls. Apart from a trend for elevated levels of interleukin 10, levels of other TH2 cytokines including interleukins 2 and 4 were too low to be accurately quantified. Mucosal interferon-gamma mRNA levels correlated with the degree of diarrhoea, and returned towards normal in remission. The immunohistochemical expression of cell junction proteins, E-cadherin and ZO-1, was reduced in active disease. No differences were noted between lymphocytic and collagenous colitis for any of the above parameters. CONCLUSIONS: MC demonstrates a TH1 mucosal cytokine profile with IFN-gamma as the predominantly up-regulated cytokine, with concurrent induction of nitric oxide synthase and down-regulation of interferon-fx-related cell junction proteins. This pattern is similar to that in coeliac disease and suggests it might represent a response to a luminal antigen.
