BioProject

Background & Aims. As a T cell-mediated disease of the colonic epithelium, ulcerative colitis (UC) is likely to share pathogenic elements with other T cell-mediated inflammatory diseases. More...

Background & Aims. As a T cell-mediated disease of the colonic epithelium, ulcerative colitis (UC) is likely to share pathogenic elements with other T cell-mediated inflammatory diseases. Recently we showed T cell-mediated rejection of kidney and heart transplants share large scale molecular changes. We hypothesized that UC would manifest a similar disturbance, and that these features would correlate with response to infliximab. Results. UC biopsies manifested coordinate transcript changes resembling rejecting transplants, with T cell, IFNG-induced, macrophage, and injury transcripts increasing while parenchymal transcripts decreased. The disturbance expressed as principal component 1 correlated with conventional assessments e.g. Mayo scores, serum albumin, and lymphoplasmacytic infiltrate. When assessed in published microarray studies, the disturbance predicted response to infliximab: patients with intense disturbance did not achieve clinical response, although quantitative improvement was usually seen even in non-responders. Similar changes were seen in Crohn’s colitis (CDc). Conclusions. The molecular phenotype of UC manifests a large scale coordinate disturbance reflecting changes in inflammatory cells and parenchymal elements that correlates with conventional features and predicts response to infliximab. Overall design: We studied 56 colon biopsies from patients with colitis, including 43 with UC, characterizing the clinical and histological features, and defined the mRNA phenotype with Affymetrix expression microarrays. We measured the expression of previously defined pathogenesis-based transcript sets representing effector T cells, macrophages, IFNG effects, and parenchymal injury response and dedifferentiation. We also studied 48 microarray files from human colon biopsies from the Gene Expression Omnibus database, classified by response to infliximab therapy to look for molecular changes that predict unresponsiveness. Less...