Ompared to normal controls (Fig. 6A). RNA transcripts for IL-23/p19 did not significantly differ between the macroscopically unaffected neo-terminal ileum and normal controls (Fig. 6A). TNF-a was up regulated in CD samples obtained from the neo-terminal 22948146 ileum, either with or without endoscopic recurrence, but not from established lesions, as compared to normal controls (Fig. 6B and Tables 1?). IL-6 was up regulated only in CD samples obtained from the neo-terminalOver-expression of Th2-cytokines Occur in Both the Macroscopically Affected Neo-terminal Ileum and Established Lesions of CD PatientsPioneering studies by Desreumaux and colleagues showed that early CD lesions are marked by enhanced gene expression of Th2 cytokines. [25] Enhanced expression of IL-4 and IL-5 was seen in CD biopsies taken from the neo-terminal ileum with endoscopic recurrence and in samples with established lesions as compared toDistinct Cytokine Patterns in CDFigure 4. IL-4, IL-5 and IL-13 are up regulated in CD tissue with early and established lesions. Transcripts for IL-4 (A), IL-5 (E) and IL-13 (F) were analysed in ileal samples taken from CD patients with no endoscopic recurrence (i0 1), CD patients with endoscopic recurrence (i2 4), CD patients with established/late lesions and normal controls by real-time PCR and normalized to b-actin. Data indicate individual values of cytokines in single biopsies and horizontal bars represent the median value. B. Flow cytometry analysis of IL-4-producing cells in CD3+LPMC isolated from CD patients with no endoscopic recurrence (i0 1), CD patients with endoscopic recurrence (i2 4), CD patients with established/late lesions and normal controls. LPMC were gated on CD3+ cells and subsequently analysed for the expression of IL-4. Data indicate individual values and horizontal bars represent the median value. Right insets: representative histograms of IL-4-producing CD3+cells in LPMC isolated from 1 CD patient with noDistinct Cytokine Patterns in CDendoscopic recurrence (i0), 1 CD patient with endoscopic recurrence (i4), 1 CD patient with established/late lesions and 1 normal control. Staining with a control IgG is also shown. Numbers above lines indicate the percentages of positive cells. C . Ratio between the percentages of IFN-cproducing (C) or IL-17A-producing (D) CD3+LPMC and IL-4-producing CD3+ LPMC isolated from 
CD patients with no endoscopic recurrence (i0 1), CD patients with endoscopic recurrence (i2 4), CD patients with established/late lesions and normal controls. doi:10.1371/journal.pone.0054562.TA01 gileum with endoscopic recurrence and established lesions (Fig. 6C and Tables 1?).DiscussionThis study was undertaken to characterize the mucosal pattern of effector cytokines in CD at different stages of the disease. To this end, we considered as “initial lesions” those developing in the neoterminal ileum of patients after a curative ileo-colonic resection and “established lesions” those seen in patients with a long-history of disease requiring intestinal resection. More than one third of CD patients did not show endoscopic signs of recurrence within the time-frame of 1 year after the ileocolonic resection, in line with previously published studies. [23,29?0] Immunofluorescence analysis of biopsies taken from this subgroup of patients showed a marked MedChemExpress 3PO infiltration of the mucosa with both CD3+ and CD68+ cells, reinforcing the notion that T cells and macrophages drive inflammatory events necessary for the development of.Ompared to normal controls (Fig. 6A). RNA transcripts for IL-23/p19 did not significantly differ between the macroscopically unaffected neo-terminal ileum and normal controls (Fig. 6A). TNF-a was up regulated in CD samples obtained from the neo-terminal 22948146 ileum, either with or without endoscopic recurrence, but not from established lesions, as compared to normal controls (Fig. 6B and Tables 1?). IL-6 was up regulated only in CD samples obtained from the neo-terminalOver-expression of Th2-cytokines Occur in Both the Macroscopically Affected Neo-terminal Ileum and Established Lesions of CD PatientsPioneering studies by Desreumaux and colleagues showed that early CD lesions are marked by enhanced gene expression of Th2 cytokines. [25] Enhanced expression of IL-4 and IL-5 was seen in CD biopsies taken from the neo-terminal ileum with endoscopic recurrence and in samples with established lesions as compared toDistinct Cytokine Patterns in CDFigure 4. IL-4, IL-5 and IL-13 are up regulated in CD tissue with early and established lesions. Transcripts for IL-4 (A), IL-5 (E) and IL-13 (F) 
were analysed in ileal samples taken from CD patients with no endoscopic recurrence (i0 1), CD patients with endoscopic recurrence (i2 4), CD patients with established/late lesions and normal controls by real-time PCR and normalized to b-actin. Data indicate individual values of cytokines in single biopsies and horizontal bars represent the median value. B. Flow cytometry analysis of IL-4-producing cells in CD3+LPMC isolated from CD patients with no endoscopic recurrence (i0 1), CD patients with endoscopic recurrence (i2 4), CD patients with established/late lesions and normal controls. LPMC were gated on CD3+ cells and subsequently analysed for the expression of IL-4. Data indicate individual values and horizontal bars represent the median value. Right insets: representative histograms of IL-4-producing CD3+cells in LPMC isolated from 1 CD patient with noDistinct Cytokine Patterns in CDendoscopic recurrence (i0), 1 CD patient with endoscopic recurrence (i4), 1 CD patient with established/late lesions and 1 normal control. Staining with a control IgG is also shown. Numbers above lines indicate the percentages of positive cells. C . Ratio between the percentages of IFN-cproducing (C) or IL-17A-producing (D) CD3+LPMC and IL-4-producing CD3+ LPMC isolated from CD patients with no endoscopic recurrence (i0 1), CD patients with endoscopic recurrence (i2 4), CD patients with established/late lesions and normal controls. doi:10.1371/journal.pone.0054562.gileum with endoscopic recurrence and established lesions (Fig. 6C and Tables 1?).DiscussionThis study was undertaken to characterize the mucosal pattern of effector cytokines in CD at different stages of the disease. To this end, we considered as “initial lesions” those developing in the neoterminal ileum of patients after a curative ileo-colonic resection and “established lesions” those seen in patients with a long-history of disease requiring intestinal resection. More than one third of CD patients did not show endoscopic signs of recurrence within the time-frame of 1 year after the ileocolonic resection, in line with previously published studies. [23,29?0] Immunofluorescence analysis of biopsies taken from this subgroup of patients showed a marked infiltration of the mucosa with both CD3+ and CD68+ cells, reinforcing the notion that T cells and macrophages drive inflammatory events necessary for the development of.