Skip to main content
Home / The International Journal of Tuberculosis and Lung Disease, Volume 25, Number 11

Incremental yield of Xpert® MTB/RIF Ultra over Xpert® MTB/RIF in the diagnosis of extrapulmonary TB

Buy Article:

$34.78 + tax (Refund Policy)

BACKGROUND: Extrapulmonary TB (EPTB) comprises approximately 15–20% of TB cases worldwide, and its diagnosis is difficult. The sensitivity of Xpert® MTB/RIF (Xpert) in the diagnosis of EPTB is low on account of its paucibacillary nature. Xpert® MTB/RIF Ultra (Ultra) was developed to improve sensitivity.

OBJECTIVE: To compare the sensitivity of Ultra test with that of Xpert against MGIT™ (Mycobacteria Growth Indicator Tube) culture and a composite reference standard (CRS).

METHODS: We recruited consecutive treatment-naïve patients with suspected EPTB. Demographic information, clinical and relevant laboratory data were collected.

RESULTS: From January 2019 to November 2019, 210 patients provided 250 samples. Against MGIT culture, the sensitivity of Ultra was significantly higher than Xpert (72% vs. 51.1%; P = 0.04), the specificity was lower (87.8% vs. 95.1%). Against the CRS also, the sensitivity of Ultra was significantly higher than Xpert (45.4% vs. 25.2%; P = 0.002); however, the specificities were similar (98.2% vs. 99.1%). The trend towards higher sensitivity of Ultra compared to Xpert was seen in most of the individual samples. The sensitivities against MGIT and CRS were as follows: lymph node (68.1% vs. 31.8%; P = 0.01) and (59.5% vs. 23.8%; P = 0.001), pleural biopsy (80.0% on both; P = NS) and (53.8% vs. 46.2%; P = NS) and pleural fluid (66.7% vs. 50%; P = NS) and (22.5% vs. 9.6%; P = NS), respectively.

CONCLUSIONS: Xpert Ultra showed a significantly higher sensitivity in diagnosing EPTB than Xpert.

Keywords: Xpert MTB/RIF Ultra; extrapulmonary tuberculosis; lymph node; pleural biopsy; pleural fluid

Document Type: Research Article

Affiliations: 1: Department of Pulmonary Medicine, Christian Medical College, Vellore, India 2: Department of General Surgery - Unit IV, Christian Medical College, Vellore, India 3: Department of Gastroenterology, Christian Medical College, Vellore, India 4: Respiratory Medicine, Christian Medical College, Vellore, India

Publication date: November 1, 2021

More about this publication?

  • The International Journal of Tuberculosis and Lung Disease (IJTLD) is for clinical research and epidemiological studies on lung health, including articles on TB, TB-HIV and respiratory diseases such as COVID-19, asthma, COPD, child lung health and the hazards of tobacco and air pollution. Individuals and institutes can subscribe to the IJTLD online or in print – simply email us at [email protected] for details.

    The IJTLD is dedicated to understanding lung disease and to the dissemination of knowledge leading to better lung health. To allow us to share scientific research as rapidly as possible, the IJTLD is fast-tracking the publication of certain articles as preprints prior to their publication. Read fast-track articles.

  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • International Journal of Tuberculosis and Lung Disease
  • Public Health Action
  • Ingenta Connect is not responsible for the content or availability of external websites

Share Content

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content