Treatment response and colonic gene expression in patients with Crohn's disease.

Objective: Responses and adverse events to medication vary greatly among patients with Crohn's disease (CD). The aim of this study was to investigate whether global gene expression profiles could predict such responses and possible side effects.
Material and Methods: Tissue specimens from the descending colon were obtained from 32 CD patients (in 18 patients from areas without inflammation and in 14 patients from inflamed areas). Gene profiling was done using the Affymetrix Human Genome U133 Plus 2.0 GeneChip array. Hybridization data were analyzed with dChip software.
Results: There were no differentially expressed genes between six patients who responded well to azathioprine and four who did not. No differences were found between 12 patients with adverse events to azathioprine and 9 patients who tolerated this drug. Sixteen patients who were not glucocorticoid-dependent had no differentially expressed genes as compared with 15 glucocorticoid-dependent patients. Six patients who responded well to infliximab had only one differentially expressed gene as compared to four patients who did not.
Conclusions: DNA microarray analyses did not show differentially expressed genetic profiles from colonic mucosal cells obtained from groups of patients classified according to therapeutic criteria.