title: Utility of in vitro interferon-γ release assay in differential diagnosis between intestinal tuberculosis and Crohn's disease.
abstract: OBJECTIVE
  To evaluate the diagnostic utility of interferon-γ release assay (T-SPOT.TB) for the differential diagnosis between Crohn's disease (CD) and intestinal tuberculosis (ITB).
  
  
  METHODS
  A total of 103 CD and 88 ITB patients, confirmed by histology and anti-tuberculosis treatment response from 2003 to 2011, were included. Their characteristics and clinical features were recorded. Mycobacterium tuberculosis (MTB) polymerase chain reaction (PCR) of IS6110, in vitro T-SPOT.TB, tuberculin skin test (TST), immunoglobulin G (IgG) antibody to MTB (protein chip), serum anti-Saccharomyces cerevisiae antibodies (ASCA IgG, chronic inflammatory bowel disease profile) and acid-fast staining of biopsied colonic tissue specimens were performed. Statistical analysis was conducted to determine their concordance with the diagnosis and its sensitivity, specificity, positive (PPV) and negative predictive value (NPV).
  
  
  RESULTS
  Abnormal pulmonary X-ray, ascites and lesions of both cecum and ascending colon were more associated with ITB, while intestinal surgery and lesions of both ileum and adjacent colon were more commonly seen in CD. Significant diagnostic concordance was found using T-SPOT.TB (κ = 0.786) by consistency test. The sensitivity, specificity, PPV and NPV of T-SPOT.TB were 86%, 93%, 88% and 91%, respectively, and the sensitivity and NPV were significantly higher than other examinations (P < 0.05).
  
  
  CONCLUSIONS
  T-SPOT.TB is a valuable assay in differentiating ITB from CD, particularly in the diagnostic exclusion of ITB based on its high specificity and NPV.
authors.affiliation: Department of Gastroenterology, Zhongnan Hospital, Wuhan University School of Medicine, Wuhan, Hubei Province, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lei
authors.forename: Feng Ming
authors.initials: FM
authors.lastname: Yi
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.forename: Rishi Vishal
authors.initials: RV
authors.lastname: Luckheeram
authors.forename: Sha
authors.initials: S
authors.lastname: Huang
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Mei Fang
authors.initials: MF
authors.lastname: Huang
authors.forename: Jin
authors.initials: J
authors.lastname: Li
authors.forename: Rui
authors.initials: R
authors.lastname: Zhou
authors.forename: Gui Fang
authors.initials: GF
authors.lastname: Yang
authors.forename: Bing
authors.initials: B
authors.lastname: Xia
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood; D000908:Antibodies, Fungal / Q000097:blood; D001201:Ascites / Q000209:etiology; D001706:Biopsy; D003106:Colon / Q000382:microbiology / Q000473:pathology*; D004396:Coloring Agents; D003424:Crohn Disease / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D004269:DNA, Bacterial / Q000032:analysis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007082:Ileum / Q000473:pathology; D007074:Immunoglobulin G / Q000097:blood; D059425:Interferon-gamma Release Tests; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000276:immunology; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D040081:Protein Array Analysis; D011859:Radiography; D012441:Saccharomyces cerevisiae / Q000276:immunology; D014374:Tuberculin Test; D014385:Tuberculosis, Gastrointestinal / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D014397:Tuberculosis, Pulmonary / Q000000981:diagnostic imaging; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D000908:Antibodies, Fungal; D004396:Coloring Agents; D004269:DNA, Bacterial; D007074:Immunoglobulin G