Differential Regulation of Peripheral Leukocyte Genes in Patients With Active Crohn's Disease and Crohn's Disease in Remission

Abstract

Assessment of disease severity is a frequent challenge in the management of Crohn's disease. Noninvasive, accurate markers for monitoring disease activity are urgently required. Specific gene expression patterns and molecular biomarkers associated with active Crohn's disease could serve as such markers, thereby providing a novel approach to disease activity monitoring. Gene expression profiling in circulating leukocytes has shown promise in several medical conditions and blood may provide an easily accessible surrogate tissue for using gene expression profiling to assess activity of Crohn's disease. In this study, we compared genome-wide transcription profiles of circulating leukocytes in patients with active and quiescent Crohn's disease. We observed complex changes in blood gene expression patterns in active Crohn's disease: genes of various functional categories were differentially regulated between active and inactive Crohn's disease. We specifically identified a number of inflammatory molecules overexpressed or underexpressed in active Crohn's disease and validated a subset of these genes by real-time reverse transcription-polymerase chain reaction. The genes differentially regulated in peripheral leukocytes represent potential new biomarkers for assessing the activity of Crohn's disease.