Comparison of xpert MTB/RIF assay, line probe assay, and culture in diagnosis of pulmonary tuberculosis on bronchoscopic specimen
Background: In patients unable to expectorate good quality sputum or with minimal to none sputum production, bronchoscopic specimens may be collected. The objective of the study is to determine the use of Xpert MTB/RIF assay and line probe assay (LPA) in the diagnosis of pulmonary TB (PTB) using sp...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Wolters Kluwer Medknow Publications
2023-01-01
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| Series: | International Journal of Mycobacteriology |
| Subjects: | |
| Online Access: | http://www.ijmyco.org/article.asp?issn=2212-5531;year=2023;volume=12;issue=2;spage=151;epage=156;aulast=Kanade |
| _version_ | 1797774227299893248 |
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| author | Swapna Kanade Zakiuddin Mohammed Anisha Kulkarni Gita Nataraj |
| author_facet | Swapna Kanade Zakiuddin Mohammed Anisha Kulkarni Gita Nataraj |
| author_sort | Swapna Kanade |
| collection | DOAJ |
| description | Background: In patients unable to expectorate good quality sputum or with minimal to none sputum production, bronchoscopic specimens may be collected. The objective of the study is to determine the use of Xpert MTB/RIF assay and line probe assay (LPA) in the diagnosis of pulmonary TB (PTB) using specimens collected by bronchoscopy in a tertiary care center. Methods: Bronchoscopy specimens received in the TB laboratory were processed by microscopy, Xpert MTB/RIF assay, LPA, and mycobacteria growth indicator tube (MGIT) culture. Results of MGIT culture are considered gold standard. Results: Of the 173 specimens tested, MTB was detected in 48 (27.74%) samples by any of the above methods. Positivity in bronchoalveolar lavage was 31.4% (44/140) and in bronchial wash was 12.1% (4/33). Detection by microscopy, Xpert assay, and culture was 20 (11.56%), 45 (26.01%), and 38 (21.96%), respectively. Culture detected MTB in three additional specimens compared to Xpert assay. Xpert assay detected MTB in 45 (26%) specimens which include 10 specimens which were negative by culture. LPA detected MTB in 18 (90%) out of 20 smear-positive specimens. RIF resistance was detected in 20 (41.7%) specimens by Xpert and/or MGIT culture drug susceptibility testing (DST). Isoniazid (INH) resistance was detected in 19 specimens by LPA and MGIT culture DST. Conclusion: Bronchoscopy can provide alternative respiratory specimens for diagnosing PTB in patients with difficulty to expectorate sputum. The utility of Xpert MTB/RIF as a rapid, sensitive, and specific test should always be supplemented with culture in difficult-to-obtain and precious respiratory specimens. LPA plays an important role in rapid detection of INH monoresistance. |
| first_indexed | 2024-03-12T22:16:57Z |
| format | Article |
| id | doaj.art-7c8e66717d5e4b71825b5a1a7bde9dbe |
| institution | Directory Open Access Journal |
| issn | 2212-5531 2212-554X |
| language | English |
| last_indexed | 2024-03-12T22:16:57Z |
| publishDate | 2023-01-01 |
| publisher | Wolters Kluwer Medknow Publications |
| record_format | Article |
| series | International Journal of Mycobacteriology |
| spelling | doaj.art-7c8e66717d5e4b71825b5a1a7bde9dbe2023-07-23T11:14:42ZengWolters Kluwer Medknow PublicationsInternational Journal of Mycobacteriology2212-55312212-554X2023-01-0112215115610.4103/ijmy.ijmy_86_23Comparison of xpert MTB/RIF assay, line probe assay, and culture in diagnosis of pulmonary tuberculosis on bronchoscopic specimenSwapna KanadeZakiuddin MohammedAnisha KulkarniGita NatarajBackground: In patients unable to expectorate good quality sputum or with minimal to none sputum production, bronchoscopic specimens may be collected. The objective of the study is to determine the use of Xpert MTB/RIF assay and line probe assay (LPA) in the diagnosis of pulmonary TB (PTB) using specimens collected by bronchoscopy in a tertiary care center. Methods: Bronchoscopy specimens received in the TB laboratory were processed by microscopy, Xpert MTB/RIF assay, LPA, and mycobacteria growth indicator tube (MGIT) culture. Results of MGIT culture are considered gold standard. Results: Of the 173 specimens tested, MTB was detected in 48 (27.74%) samples by any of the above methods. Positivity in bronchoalveolar lavage was 31.4% (44/140) and in bronchial wash was 12.1% (4/33). Detection by microscopy, Xpert assay, and culture was 20 (11.56%), 45 (26.01%), and 38 (21.96%), respectively. Culture detected MTB in three additional specimens compared to Xpert assay. Xpert assay detected MTB in 45 (26%) specimens which include 10 specimens which were negative by culture. LPA detected MTB in 18 (90%) out of 20 smear-positive specimens. RIF resistance was detected in 20 (41.7%) specimens by Xpert and/or MGIT culture drug susceptibility testing (DST). Isoniazid (INH) resistance was detected in 19 specimens by LPA and MGIT culture DST. Conclusion: Bronchoscopy can provide alternative respiratory specimens for diagnosing PTB in patients with difficulty to expectorate sputum. The utility of Xpert MTB/RIF as a rapid, sensitive, and specific test should always be supplemented with culture in difficult-to-obtain and precious respiratory specimens. LPA plays an important role in rapid detection of INH monoresistance.http://www.ijmyco.org/article.asp?issn=2212-5531;year=2023;volume=12;issue=2;spage=151;epage=156;aulast=Kanadebronchoscopy specimenline probe assaymycobacteria growth indicator tubepulmonary tuberculosisxpert assay |
| spellingShingle | Swapna Kanade Zakiuddin Mohammed Anisha Kulkarni Gita Nataraj Comparison of xpert MTB/RIF assay, line probe assay, and culture in diagnosis of pulmonary tuberculosis on bronchoscopic specimen International Journal of Mycobacteriology bronchoscopy specimen line probe assay mycobacteria growth indicator tube pulmonary tuberculosis xpert assay |
| title | Comparison of xpert MTB/RIF assay, line probe assay, and culture in diagnosis of pulmonary tuberculosis on bronchoscopic specimen |
| title_full | Comparison of xpert MTB/RIF assay, line probe assay, and culture in diagnosis of pulmonary tuberculosis on bronchoscopic specimen |
| title_fullStr | Comparison of xpert MTB/RIF assay, line probe assay, and culture in diagnosis of pulmonary tuberculosis on bronchoscopic specimen |
| title_full_unstemmed | Comparison of xpert MTB/RIF assay, line probe assay, and culture in diagnosis of pulmonary tuberculosis on bronchoscopic specimen |
| title_short | Comparison of xpert MTB/RIF assay, line probe assay, and culture in diagnosis of pulmonary tuberculosis on bronchoscopic specimen |
| title_sort | comparison of xpert mtb rif assay line probe assay and culture in diagnosis of pulmonary tuberculosis on bronchoscopic specimen |
| topic | bronchoscopy specimen line probe assay mycobacteria growth indicator tube pulmonary tuberculosis xpert assay |
| url | http://www.ijmyco.org/article.asp?issn=2212-5531;year=2023;volume=12;issue=2;spage=151;epage=156;aulast=Kanade |
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