title: [Two selected commercially based nucleic acid amplification tests for the diagnosis of tuberculosis].
abstract: BACKGROUND
  This is the retrospective study on diagnostic effectiveness of two nucleic acid amplification tests: AMPLICOR Mycobacterium tuberculosis (MTB) and Xpert MTB/RIF. The first one was included into diagnostic procedure for tuberculosis from 1999 to 2009 and the second one has been used from November 2009.
  
  
  METHODS
  Study groups comprised 1875 samples for AMPLICOR MTB (104 were inhibited), and 213 samples for Xpert MTB/RIF.
  
  
  RESULTS
  The assay sensitivity was 81.9% for AMPLICOR MTB and 81.8% for Xpert MTB/RIF, and specificity was 97.2% and 99.5% respectively, as compared to the culture on Loewenstein-Jensen medium. However, sensitivity of each test correlated with Ziehl-Neelsen staining. For AFB+ samples, assay sensitivity was 97.8% for AMPLICOR MTB and 100% for Xpert MTB/RIF and for AFB- samples it was 58.1% and 50% respectively.
  
  
  CONCLUSIONS
  The reported results show a high diagnostic usefulness of Xpert MTB/RIF test for samples, which are positive for Ziehl-Neelsen staining.
authors.affiliation: Katedra i Klinika Chorób Wewnętrznych, Pneumonologii i Alergologii Warszawskiego Uniwersytetu Medycznego, 02-097 Warszawa. aleksandra.safianowska@wum.edu.pl
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Safianowska
authors.forename: Renata
authors.initials: R
authors.lastname: Walkiewicz
authors.forename: Patrycja
authors.initials: P
authors.lastname: Nejman-Gryz
authors.forename: Hanna
authors.initials: H
authors.lastname: Grubek-Jaworska
mesh_terms: D004269:DNA, Bacterial / Q000302:isolation & purification; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis* / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial