title: Using gene expression data to identify certain gastro-intestinal diseases.
abstract: BACKGROUND
  Inflammatory bowel diseases, ulcerative colitis and Crohn's disease are considered to be of autoimmune origin, but the etiology of irritable bowel syndrome remains elusive. Furthermore, classifying patients into irritable bowel syndrome and inflammatory bowel diseases can be difficult without invasive testing and holds important treatment implications. Our aim was to assess the ability of gene expression profiling in blood to differentiate among these subject groups.
  
  
  METHODS
  Transcript levels of a total of 45 genes in blood were determined by quantitative real-time polymerase chain reaction (RT-PCR). We applied three separate analytic approaches; one utilized a scoring system derived from combinations of ratios of expression levels of two genes and two different support vector machines.
  
  
  RESULTS
  All methods discriminated different subject cohorts, irritable bowel syndrome from control, inflammatory bowel disease from control, irritable bowel syndrome from inflammatory bowel disease, and ulcerative colitis from Crohn's disease, with high degrees of sensitivity and specificity.
  
  
  CONCLUSIONS
  These results suggest these approaches may provide clinically useful prediction of the presence of these gastro-intestinal diseases and syndromes.
authors.affiliation: Department of Mathematics, Vanderbilt University, Nashville, TN, USA. philip.s.crooke@vanderbilt.edu.
authors.forename: Philip S
authors.initials: PS
authors.lastname: Crooke
authors.forename: John T
authors.initials: JT
authors.lastname: Tossberg
authors.forename: Sara N
authors.initials: SN
authors.lastname: Horst
authors.forename: John L
authors.initials: JL
authors.lastname: Tauscher
authors.forename: Melodie A
authors.initials: MA
authors.lastname: Henderson
authors.forename: Dawn B
authors.initials: DB
authors.lastname: Beaulieu
authors.forename: David A
authors.initials: DA
authors.lastname: Schwartz
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Olsen
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Aune