TH1/TH17 profiles in crohn's disease: a cross sectional single centre study in postoperative crohn's disease

Introduction Th1 and Th17 pathways are implicated in Crohn's disease (CD). In operative resection samples healthy ileum shows high TGFβ levels in patients who develop recurrence, with TGFβ being a known activator of the Th17 response. Other studies in CD show a dominant Th1 cytokine profile, with high levels of IFNγ, which reduce Th17 response and augment Th1 response. The relationship of Th1/Th17 cytokine profiles in postoperative CD has not been examined. The authors aimed to study tissue Th1/Th17 cytokine secretion after in vitro biopsy culture in postoperative CD. Methods Colonoscopy was undertaken in postoperative CD patients. Recurrence graded as no/minimal inflammation (Rutgeert Score (RS) ≥1) or progressive inflammation (RS≥2). Ileal biopsies were cultured overnight and cell free supernatants obtained. Supernatant cytokines (IL-2, IL-4, IL-10, IL-17 TNFα, INFg and IL-6) were assessed by flow cytometry using cytometric bead array (Becton Dickinson). Statistical analysis was via unpaired t tests. Results Consecutive patients attending endoscopy (n=24, 9M/15F) were identified. Mean age 45.0 years and time from I to C resection was 5.8 years; 5 patients were smokers. Drugs were thiopurines 13, Infliximab 1 and nil 10. Endoscopic severity was i0 n=5, i1 n=6, i2 n=5, i3 n=3, i4 n=5. Mean cytokine concentrations from supernatants are shown in the table 1. Comparison between RS≥1 and ≥2 showed that pro-inflammatory cytokines IL-17a (p