title: The role of in vitro interferonγ-release assay in differentiating intestinal tuberculosis from Crohn's disease in China.
abstract: OBJECTIVE
  Intestinal tuberculosis (ITB) and Crohn's disease (CD) have overlapping clinical, radiographic, endoscopic and histologic features, which makes the distinction between these two disease entities a great challenge in tuberculosis-endemic countries. The aim of the study was to investigate the value of in vitro interferonγ release assay (T-SPOT.TB) in differentiating ITB from CD.
  
  
  METHODS
  From June 2008 to February 2010, a total of 93 consecutive patients with undetermined ITB or CD were prospectively recruited. Clinical, endoscopic, histologic and therapeutic responses were longitudinally monitored at follow-up evaluation until the final definite diagnosis has been reached.
  
  
  RESULTS
  After a median of 6 months' follow-up (interquartile range [IQR], 3.0 to 7.5 months), definitive diagnosis was achieved in 84 of the 93 patients (90%), with 19 having ITB and 65 having CD. On univariate analysis, a long duration of illness, chronic diarrhea, and anemia were significantly more common in CD (P<0.05). While night sweat, ascites, pulmonary lesions, circumferential ulcer on endoscopy, ileo-cecal valve involvement and epithelioid granulomas were significantly more common in ITB (P<0.05). On multivariate analysis, T-SPOT.TB (Hazard ratio 7.0, 95% confidence interval [CI] 1.9-25.7) was found to be a good predictor for ITB diagnosis. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of T-SPOT.TB were 84.2%, 75.4%, 50.0%, and 94.2%, respectively.
  
  
  CONCLUSIONS
  When differentiating ITB and CD in tuberculosis-endemic regions, T-SPOT.TB blood test may be a helpful and practical diagnostic tool for its high NPV to rule out ITB.
authors.affiliation: Division of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100730, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.forename: Li-fan
authors.initials: LF
authors.lastname: Zhang
authors.forename: Xiao-qing
authors.initials: XQ
authors.lastname: Liu
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Xi
authors.initials: X
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Jia-ming
authors.initials: JM
authors.lastname: Qian
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000740:Anemia / Q000209:etiology; D001201:Ascites / Q000382:microbiology; D016009:Chi-Square Distribution; D002681:China; D002908:Chronic Disease; D003424:Crohn Disease / Q000150:complications / Q000175:diagnosis*; D003937:Diagnosis, Differential; D003967:Diarrhea / Q000209:etiology; D005260:Female; D006099:Granuloma / Q000382:microbiology; D006801:Humans; D007077:Ileal Diseases / Q000382:microbiology; D007371:Interferon-gamma / Q000097:blood*; D008171:Lung Diseases / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D013601:T-Lymphocytes / Q000378:metabolism*; D014385:Tuberculosis, Gastrointestinal / Q000150:complications / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D007371:Interferon-gamma