Expression data from colonic biopsy samples of infliximab treated UC patients

A gene expression profiling sub-study was conducted in which colonic biopsy samples were collected for RNA extraction and hybridization to microarrays from 48 patients with UC who were participating in ACT 1, a placebo-controlled study of infliximab. Gene expression profiles from infliximab responders were compared with those of baseline and infliximab non-responder samples. Infliximab had a significant effect on mRNA expression in treatment responders, with both infliximab dose and duration of treatment having an effect. Genes affected are primarily involved with inflammatory response, cell-mediated immune responses, and cell-to-cell signaling. Infliximab non-responders had a molecular phenotype that closely resembled that of untreated patients with UC. Unlike responders, non-responders do not effectively modulate TH1, TH2, and TH17 pathways. Gene expression can differentiate placebo and infliximab responders. Patients with moderate-to-severe, active UC were treated with infliximab or placebo at weeks 0, 2, 6 and every 8 weeks thereafter. Biopsy samples (n=113) were collected from 48 patients at baseline, weeks 8 and 30 for RNA extraction and microarray analysis.