title: Differential expression of miR-31 between inflammatory bowel disease and microscopic colitis.
abstract: BACKGROUND
  Idiopathic inflammatory bowel disease (IBD) and microscopic colitis (MC) are distinct entities. However, patients with intermittent episodes of IBD and MC that are encountered in a clinical setting puzzle clinicians and pathologists. This study examined whether microRNA assisted in the classification of IBD and MC.
  
  
  METHODS
  Small RNA was extracted from formalin-fixed, paraffin-embedded (FFPE) colon tissue and qRT-PCR was performed from cohorts of normal control (n=38), ulcerative colitis (n=36), Crohns disease (n=26), collagenous colitis (n=36), lymphocytic colitis (n=30), and patients with intermittent features of IBD and MC (n=6).
  
  
  RESULTS
  Differential expression of miR-31 distinguished IBD (ulcerative colitis and Crohns disease) from MC (collagenous colitis and lymphocytic colitis), confirming the specificity of miR-31 expression in IBD (P=0.00001). In addition, expression of miR-31 was increased in collagenous colitis compared to that of lymphocytic colitis (P=0.010). Among 6 patients with alternating episodes of IBD and MC, one patient had matching miR-31 expression in different phases (lymphocytic colitis to ulcerative colitis, and then back to collagenous colitis). The other 5 patients had MC-like expression patterns in both MC and IBD episodes.
  
  
  CONCLUSIONS
  In summary, IBD and MC have distinct miR-31 expression pattern. Therefore, miR-31 might be used as a biomarker to distinguish between IBD and MC in FFPE colonic tissue. In addition, miR-31 is differentially expressed in colonic tissue between lymphocytic colitis and collagenous colitis, suggesting them of separate disease processes. Finally, patients with alternating IBD and MC episodes represent a diverse group. Among them, the majority demonstrates MC-like miR-31 expression pattern in MC phases, which seems unlikely to support the speculation of MC as an inactive form of IBD. Although the mechanisms deserve further investigation, microRNA is a potentially useful biomarker to differentiate IBD and MC.
authors: Chen
authors: C
authors: Zhang
authors: Zijin
authors: Z
authors: Zhao
authors: Hany
authors: H
authors: Osman
authors: Rao
authors: R
authors: Watson
authors: Ilke
authors: I
authors: Nalbantoglu
authors: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 350 West 11th Street, Indianapolis, IN, 46202, USA.
authors: Jingmei
authors: J
authors: Lin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D046728:Colitis, Microscopic / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D003093:Colitis, Ulcerative / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D003424:Crohn Disease / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged
chemical_list: D015415:Biomarkers; C534612:MIRN31 microRNA, human; D035683:MicroRNAs