Mucosal expression profiling in patients with inflammatory bowel disease before and after first infliximab treatment

We used microarrays to identify mucosal gene signatures predictive of response to infliximab (IFX) in patients with inflammatory bowel disease (IBD) and to gain more insight into the pathogenesis of IBD. Keywords: drug response and treatment effect Mucosal biopsies were obtained at endoscopy in actively inflamed mucosa from 61 IBD patients (24 ulcerative colitis (UC), 19 Crohn’s colitis (CDc) and 18 Crohn’s ileitis (CDi)), refractory to corticosteroids and/or immunosuppression, before and 4-6 weeks after (except for 1 CDc patient) their first infliximab infusion and in normal mucosa from 12 control patients (6 colon and 6 ileum). The patients were classified for response to infliximab based on endoscopic and histologic findings at 4-6 weeks after first infliximab treatment. Total RNA was isolated from intestinal mucosal biopsies, labelled and hybridized to Affymetrix Human Genome U133 Plus 2.0 Arrays.