Efficacy of the Xpert Mycobacterium tuberculosis/rifampicin assay for diagnosing sputum-smear negative or sputum-scarce pulmonary tuberculosis in bronchoalveolar lavage fluid.

Abstract

OBJECTIVE:

To evaluate he diagnostic performance of the Xpert Mycobacterium tuberculosis/Rifampin (MTB/RIF) assay in bronchoalveolar lavage fluid (BALF).

METHODS:

We retrospectively reviewed the clinical data from 671 sputum-smear negative or sputum-scarce adult patients with suspected pulmonary tuberculosis (PTB) who had an Xpert MTB/RIF assay performed on BALF. The diagnostic performance of the Xpert MTB/RIF assay, smear microscopy (SM) and MTB culture was evaluated using MTB culture or final clinical diagnosis as the reference standard.

RESULTS:

Compared with MTB culture, the sensitivity and specificity were 87.8% and 72.7% for the Xpert MTB/RIF assay and 11.0% and 99.2% for SM, respectively. Compared with final diagnosis, diagnostic performance was 58.9% and 83.9% for the Xpert MTB/RIF assay, 5.0% and 98.3% for SM, and 43.3% and 100% for culture, for sensitivity and specificity respectively. The Xpert MTB/RIF assay had low specificity and high sensitivity. When very low results were re-evaluated and considered MTB-negative, the specificity increased significantly. The sensitivity remained higher than SM and was similar to that of culture.

CONCLUSIONS:

The Xpert MTB/RIF assay adds microbiologic evidence to clinical decisions; however, close attention should be paid to very low semi-quantitative positive results.

• Authors: Juan Yang, Yanheng Shen, Lei Wang, LiXia Ju, Xiaocui Wu, Peng Wang, Xiaohui Hao, Qin Sun, Fangyou Yu, Wei Sha
• Journal: International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases (Int J Infect Dis) Vol. 107 Pg. 121-126 (Jun 2021) ISSN: 1878-3511 [Electronic] Canada
• PMID: 33864923 (Publication Type: Journal Article)
• Copyright: Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Chemical References

• Rifampin

Topics

• Adult
• Bronchoalveolar Lavage Fluid (microbiology)
• Humans
• Male
• Middle Aged
• Mycobacterium tuberculosis (drug effects)
• Retrospective Studies
• Rifampin (pharmacology)
• Sensitivity and Specificity
• Sputum (microbiology)