Detection of Mycobacterium tuberculosis Complex in Paraffin-Embedded Tissues by the New Automated Abbott RealTime MTB Assay

Ann Clin Lab Sci. 2016 Jul;46(4):412-7.

Abstract

Objective: The Abbott RealTime MTB assay, launched in June 2014, has been shown to have a competitive performance in the detection of the Mycobacterium tuberculosis (MTB) complex in respiratory specimens. The present study was conducted to investigate the usefulness of the Abbott MTB Realtime assay in the detection of MTB in formalin-fixed paraffin-embedded (FFPE) tissues.

Methods: A total of 96 FFPE specimens obtained from microbiologically proven MTB cases (N=60) and nontuberculous Mycobacterium cases (N=36) were analyzed. The performance of the Abbott MTB Realtime assay was compared with that of the Roche Cobas TaqMan MTB assay.

Results: The overall sensitivity and specificity of the Abbott assay were 63.3% and 97.2%, respectively, compared with 11.7% and 100% for the Cobas assay. The detection rate of the Abbott assay was much higher among 37 acid-fast-positive specimens than among 23 acid-fast-negative specimens (89.3% versus 21.7%, respectively). The detection rate of the assay was higher among 29 resection specimens than among 31 small biopsy specimens (86.2% versus 41.9%, respectively).

Conclusion: Our results suggest that the Abbott RealTime MTB assay can be used to differentiate MTB from nontuberculous mycobacterial infections in acid-fast-positive FFPE tissues.

MeSH terms

  • Automation
  • Formaldehyde
  • Humans
  • Mycobacterium tuberculosis / isolation & purification*
  • Paraffin Embedding / methods*
  • Reagent Kits, Diagnostic*
  • Tissue Fixation
  • Tuberculosis, Pulmonary / diagnosis*
  • Tuberculosis, Pulmonary / microbiology*

Substances

  • Reagent Kits, Diagnostic
  • Formaldehyde