title: CD99 refers to the activity of inflammatory bowel disease.
abstract: BACKGROUND
  Inflammatory bowel disease (IBD), composed of Crohn's disease (CD) and ulcerative colitis (UC), is an inflammatory autoimmune disease. CD99 has been reported to participate in migration of leukocytes and T cell activation. However, the roles of CD99 in IBD are obscure.
  
  
  METHODS
  CD99 expression was examined in peripheral blood mononuclear cells (PBMCs) and inflamed mucosa from IBD patients by qRT-PCR. Serum TNF-α and IL-17A levels were detected by ELISA. Correlations of CD99 expression with TNF-α, IL-17A, Crohn's disease activity index (CDAI), simple endoscopic score for CD (SES-CD), Mayo index, and Truelove grading were performed by Pearson's correlation.
  
  
  RESULTS
  CD99 expression was increased in PBMCs and inflamed mucosa from active CD and UC patients, and CD99 expression was also increased in the inflamed mucosa compared with unaffected control from the same patients. Serum TNF-α and IL-17A levels were increased in active CD or UC patients, and positively correlated with CD99 expression in PBMCs (CD: r = .402, p = .009; r = .350, p = .025. UC: r = .289, p = .028; r = .322, p = .014). Moreover, CD99 expression in inflamed mucosa was correlated with CDAI, SES-CD, Mayo index, and Truelove grading (r = .410, p = .012; r = .341, p = .005; r = .366, p = .002; r = .312, p = .011).
  
  
  CONCLUSIONS
  CD99 expression is increased in patients with active IBD, and positively correlated with disease activity. Therefore, CD99 expression can be used as an index to evaluate the activity of IBD.
authors.affiliation: a Department of Gastroenterology , The Shanghai Tenth People's Hospital, Tongji University , Shanghai , China.
authors.forename: Guangxi
authors.initials: G
authors.lastname: Zhou
authors.affiliation: a Department of Gastroenterology , The Shanghai Tenth People's Hospital, Tongji University , Shanghai , China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Yang
authors.affiliation: a Department of Gastroenterology , The Shanghai Tenth People's Hospital, Tongji University , Shanghai , China.
authors.forename: Lin
authors.initials: L
authors.lastname: Yu
authors.affiliation: a Department of Gastroenterology , The Shanghai Tenth People's Hospital, Tongji University , Shanghai , China.
authors.forename: Tianming
authors.initials: T
authors.lastname: Yu
authors.affiliation: a Department of Gastroenterology , The Shanghai Tenth People's Hospital, Tongji University , Shanghai , China.
authors.forename: Zhanju
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000071443:12E7 Antigen / Q000235:genetics / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002681:China; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D020381:Interleukin-17 / Q000097:blood*; D007413:Intestinal Mucosa / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*; D055815:Young Adult
chemical_list: D000071443:12E7 Antigen; C061828:CD99 protein, human; D020381:Interleukin-17; D014409:Tumor Necrosis Factor-alpha
keywords: CD99; Inflammatory bowel disease; disease activity; mucosal inflammation