title: Factors Contributing to False-Negative Enzyme-Linked Immunospot Assay for Interferon-Gamma Results in Active Tuberculosis.
abstract: BACKGROUND
  The enzyme-linked immunospot assay test (T-SPOT.TB) is effective for detecting TB, but there are still some persons with tuberculosis (TB) who have negative results. The aim of this study was to analyze the factors that contribute to false negative results in active TB patients.
  
  
  METHODS
  We investigated the clinical trial and laboratory data of the active TB patients hospitalized in the First Affiliated Hospital of Xi'an Jiaotong University from May 2013 to November 2014.
  
  
  RESULTS
  In 556 active TB patients, 198 infected sites were pulmonary, 358 infected sites were extra pulmonary, and 13.85% (77/556) had false negative T SPOT.TB results. The univariate and multivariate analysis showed that age and bone/joint TB were the factors contributing to the T-SPOT. TB false negative results and pleural TB were related to true positive results.
  
  
  CONCLUSIONS
  The site of TB may significantly affect the sensitivity of T-SPOT.TB. False negative results of TSPOT.TB are associated with older age and bone/joint TB, so in older adult patients or those with bone/joint TB, the exclusion of TB should be regarded with caution when T-SPOT.TB results are negative.
authors.forename: Guoli
authors.initials: G
authors.lastname: Lian
authors.forename: Fangxiong
authors.initials: F
authors.lastname: Du
authors.forename: Hongyan
authors.initials: H
authors.lastname: Wu
authors.forename: Min
authors.initials: M
authors.lastname: He
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Liu
mesh_terms: D058501:Enzyme-Linked Immunospot Assay; D006801:Humans; D007371:Interferon-gamma; D059425:Interferon-gamma Release Tests; D014376:Tuberculosis
chemical_list: D007371:Interferon-gamma