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Discordance between MTB/RIF and Real-Time Tuberculosis-Specific Polymerase Chain Reaction Assay in Bronchial Washing Specimen and Its Clinical Implications.
- Source :
-
PloS one [PLoS One] 2016 Oct 19; Vol. 11 (10), pp. e0164923. Date of Electronic Publication: 2016 Oct 19 (Print Publication: 2016). - Publication Year :
- 2016
-
Abstract
- The prevalence and clinical implications of discordance between Xpert MTB/RIF assays and the AdvanSure TB/NTM real-time polymerase chain reaction (PCR) for bronchial washing specimens have not been studied in pulmonary TB (PTB) patients. The discordant proportion and its clinical impact were evaluated in 320 patients from the bronchoscopy registry whose bronchial washing specimens were tested simultaneously with Xpert MTB/RIF and the TB/NTM PCR assay for three years, and the accuracy of the assays, including the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were studied. The clinical risk factors for discordance and false positivity of assays were also studied. Among 130 patients who were clinically diagnosed with PTB, 64 patients showed positive acid-fast bacilli culture results, 56 patients showed positive results in molecular methods and clinician diagnosed PTB without results of microbiology in 10 patients. The sensitivity, specificity, PPV, and NPV were 80.0%, 98.95%, 98.1%, and 87.9%, respectively, for Xpert MTB/RIF and 81.5%, 92.6%, 88.3%, and 88.0%, respectively, for TB/NTM PCR. The discordant proportion was 16.9% and was higher in culture-negative PTB compared to culture-confirmed PTB (24.3% vs. 9.4%, p = 0.024). However, there were no significant differences in the clinical characteristics, regardless of the discordance. The diagnostic yield increased with an additional assay (7.7% for Xpert MTB/RIF and 9.2% for TB/NTM PCR). False positivity was less common in patients tested with Xpert MTB/RIF (1.05% vs. 7.37%, p = 0.0035). No host-related risk factor for false positivity was identified. The Xpert MTB/RIF and TB/NTM PCR assay in bronchial washing specimens can improve the diagnostic yields for PTB, although there were considerable discordant results without any patient-related risk factors.<br />Competing Interests: The authors have declared that no competing interests exist.
- Subjects :
- Aged
Aged, 80 and over
Bacteriological Techniques methods
Bronchoalveolar Lavage
Early Diagnosis
Female
Humans
Male
Middle Aged
Real-Time Polymerase Chain Reaction
Sensitivity and Specificity
Sputum microbiology
Tuberculosis, Pulmonary microbiology
Bronchoalveolar Lavage Fluid microbiology
Mycobacterium tuberculosis genetics
Mycobacterium tuberculosis growth & development
Tuberculosis, Pulmonary diagnosis
Subjects
Details
- Language :
- English
- ISSN :
- 1932-6203
- Volume :
- 11
- Issue :
- 10
- Database :
- MEDLINE
- Journal :
- PloS one
- Publication Type :
- Academic Journal
- Accession number :
- 27760181
- Full Text :
- https://doi.org/10.1371/journal.pone.0164923