Polepole, P;
Kabwe, M;
Kasonde, M;
Tembo, J;
Shibemba, A;
O'Grady, J;
Kapata, N;
... Bates, M; + view all
(2017)
Performance of the Xpert MTB/RIF assay in the diagnosis of tuberculosis in formalin-fixed, paraffin-embedded tissues.
International Journal of Mycobacteriology
, 6
(1)
pp. 87-93.
10.4103/2212-5531.201892.
Preview |
Text
Zumla_IntJMycobacteriol6187-4373868_120858.pdf - Published Version Download (531kB) | Preview |
Abstract
OBJECTIVE/BACKGROUND: Extrapulmonary tuberculosis (EPTB), which accounts for 10%-40% of the global burden of TB, with the highest incidence in Sub-Saharan Africa, is strongly associated with human immunodeficiency virus infection. Diagnosing EPTB is challenging, and recently, there has been a concerted effort to evaluate the latest molecular diagnostics for diagnosing TB in a range of specimen types. The Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA, USA) is one such technology, which simultaneously detects Mycobacterium tuberculosis and rifampicin resistance. Our objective was to evaluate the accuracy of the Xpert MTB/RIF assay for the diagnosis of EPTB and detection of rifampicin resistance in routinely processed formalin-fixed, paraffin-embedded (FFPE) tissues, compared with histological detection of TB as the gold standard. METHODS: A convenience set of 100 biobanked FFPE tissues, including lymph nodes (n = 64), male genital tract tissue (n = 10), abdominal tissue (n = 8), female genital tissue (n = 5), breast tissue (n = 5), synovial tissue (n = 4), skin (n = 2), tongue tissue (n = 1), and thyroid (n = 1), from routine cases of clinically suspected EPTB admitted to the University Teaching Hospital, Lusaka, Zambia, were analyzed using the Xpert MTB/RIF assay and in-house polymerase chain reaction (PCR) assay targeting IS6110, in parallel with Ziehl-Neelsen (ZN) staining, against histology as the gold standard. RESULTS: Some 66% of specimens had histological evidence of TB infection. ZN staining was positive for TB in 8% of cases, and Xpert MTB/RIF was positive for TB in 25% of cases. Taking histology as the gold standard, the sensitivity and specificity were as follows: In lymph tissue the accuracy of the Xpert MTB/RIF assay was 41% (95%CI 27-57), not significantly better than ZN or the in-house PCR assay. In non-lymph tissue the sensitivity of the in-house PCR assay was 82% (95%CI: 56%-95%), significantly higher than the Xpert MTB/RIF assay (P = 0.004). The Xpert MTB/RIF assay indicated rifampicin resistance in just three cases. CONCLUSION: The Xpert MTB/RIF assay is potentially a useful tool for the diagnosis of TB in routine FFPE tissues.
| Type: | Article |
|---|---|
| Title: | Performance of the Xpert MTB/RIF assay in the diagnosis of tuberculosis in formalin-fixed, paraffin-embedded tissues |
| Location: | Netherlands |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.4103/2212-5531.201892 |
| Publisher version: | http://doi.org/10.4103/2212-5531.201892 |
| Language: | English |
| Additional information: | © 2017 The International Journal of Mycobacteriology. This is an open access article distributed under the terms of the Creative Commons Attribution‑NonCommercial‑ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non‑commercially, as long as the author is credited and the new creations are licensed under the identical terms. |
| Keywords: | Formalin‑fixed paraffin‑embedded, histopathology, tuberculosis, Xpert MTB/RIF, Zambia, Ziehl–Neelsen |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences > Div of Infection and Immunity |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1551410 |
Loading...
Loading...Loading...| 1. |  China | 9 |
| 2. |  United States | 7 |
| 3. |  Portugal | 1 |
| 4. |  United Kingdom | 1 |
| 5. |  Peru | 1 |
| 6. |  Philippines | 1 |
| 7. |  Russian Federation | 1 |
| 8. |  Brazil | 1 |
| 9. |  India | 1 |
| 10. |  Pakistan | 1 |
Archive Staff Only
 |
View Item |
