Comparison of same day diagnostic tools including Gene Xpert and unstimulated IFN-γ for the evaluation of pleural tuberculosis: a prospective cohort study

 

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dc.contributor.author Meldau, Richard
dc.contributor.author Peter, Jonny
dc.contributor.author Theron, Grant
dc.contributor.author Calligaro, Greg
dc.contributor.author Allwood, Brian
dc.contributor.author Symons, Greg
dc.contributor.author Khalfey, Hoosain
dc.contributor.author Ntombenhle, Gina
dc.contributor.author Govender, Ureshnie
dc.contributor.author Binder, Anke
dc.contributor.author van Zyl-Smit, Richard
dc.contributor.author Dheda, Keertan
dc.date.accessioned 2015-01-27T11:48:33Z
dc.date.available 2015-01-27T11:48:33Z
dc.date.issued 2014-04-08
dc.identifier.citation Meldau et al.: Comparison of same day diagnostic tools including Gene Xpert and unstimulated IFN-γ for the evaluation of pleural tuberculosis: a prospective cohort study.BMC Pulmonary Medicine. 2014 14(1):58 en_ZA
dc.identifier.issn 1471-2466 en_ZA
dc.identifier.uri http://hdl.handle.net/11427/12334
dc.identifier.uri http://dx.doi.org/10.1186/1471-2466-14-58
dc.description.abstract Background: The accuracy of currently available same-day diagnostic tools (smear microscopy and conventional nucleic acid amplification tests) for pleural tuberculosis (TB) is sub-optimal. Newer technologies may offer improved detection. Methods: Smear-microscopy, adenosine deaminase (ADA), interferon gamma (IFN-γ), and Xpert MTB/RIF [using an unprocessed (1 ml) and centrifuged (~20 ml) sample] test accuracy was evaluated in pleural fluid from 103 consecutive patients with suspected pleural TB. Culture for M.tuberculosis and/or histopathology (pleural biopsy) served as the reference standard. Patients were followed prospectively to determine their diagnostic categorisation. Results: Of 93 evaluable participants, 40 had definite-TB (reference positive), 5 probable-TB (not definite but treated for TB) and 48 non-TB (culture and histology negative, and not treated for TB). Xpert MTB/RIF sensitivity and specificity (95% CI) was 22.5% (12.4 - 37.6) and 98% (89.2 - 99.7), respectively, and centrifugation did not improve sensitivity (23.7%). The Xpert MTB/RIF internal positive control showed no evidence of inhibition. Biomarker specific sensitivity, specificity, PPV, and NPVs were: ADA (48.85 IU/L; rule-in cut-point) 55.3% (39.8 - 69.9), 95.2% (83.9 - 98.7), 91.4 (73.4 - 95.4), 69.7% (56.7 - 80.1); ADA (30 IU/L; clinically used cut-point) 79% (63.7 - 89), 92.7% (80.6 - 97.5), 91.0 (73.4 - 95.4), 82.7% (69.3 - 90.1); and IFN-γ (107.7 pg/ml; rule-in cut-point) 92.5% (80.2 - 97.5), 95.9% (86.1 - 98.9), 94.9% (83.2 - 98.6), 93.9% (83.5 - 97.9), respectively (IFN-γ sensitivity and NPV better than Xpert [p < 0.05] and rule-in ADA [p < 0.05]). Conclusion: The usefulness of Xpert MTB/RIF to diagnose pleural TB is limited by its poor sensitivity. IFN-γ is an excellent rule-in test and, compared to ADA, has significantly better sensitivity and rule-out value in a TB-endemic setting. en_ZA
dc.language eng en_ZA
dc.publisher BioMed Central en_ZA
dc.rights Attribution 2.0 Generic (CC BY 2.0) *
dc.rights.uri http://creativecommons.org/licenses/by/2.0/ en_ZA
dc.source BMC Pulmonary Medicine en_ZA
dc.source.uri http://www.biomedcentral.com/1471-2466
dc.subject.other Tuberculosis en_ZA
dc.subject.other Xpert MTB/RIF en_ZA
dc.subject.other Interferon gamma en_ZA
dc.subject.other Adenosine deaminase en_ZA
dc.subject.other Pleural fluid en_ZA
dc.title Comparison of same day diagnostic tools including Gene Xpert and unstimulated IFN-γ for the evaluation of pleural tuberculosis: a prospective cohort study en_ZA
dc.type Journal Article en_ZA
dc.date.updated 2015-01-15T17:55:09Z
dc.language.rfc3066 en
dc.rights.holder Meldau et al.; licensee BioMed Central Ltd.
uct.type.publication Research en_ZA
uct.type.resource Article en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Health Sciences en_ZA
dc.publisher.department Division of Pulmonology en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Meldau, R., Peter, J., Theron, G., Calligaro, G., Allwood, B., Symons, G., ... Dheda, K. (2014). Comparison of same day diagnostic tools including Gene Xpert and unstimulated IFN-γ for the evaluation of pleural tuberculosis: a prospective cohort study. <i>BMC Pulmonary Medicine</i>, http://hdl.handle.net/11427/12334 en_ZA
dc.identifier.chicagocitation Meldau, Richard, Jonny Peter, Grant Theron, Greg Calligaro, Brian Allwood, Greg Symons, Hoosain Khalfey, et al "Comparison of same day diagnostic tools including Gene Xpert and unstimulated IFN-γ for the evaluation of pleural tuberculosis: a prospective cohort study." <i>BMC Pulmonary Medicine</i> (2014) http://hdl.handle.net/11427/12334 en_ZA
dc.identifier.vancouvercitation Meldau R, Peter J, Theron G, Calligaro G, Allwood B, Symons G, et al. Comparison of same day diagnostic tools including Gene Xpert and unstimulated IFN-γ for the evaluation of pleural tuberculosis: a prospective cohort study. BMC Pulmonary Medicine. 2014; http://hdl.handle.net/11427/12334. en_ZA
dc.identifier.ris TY - Journal Article AU - Meldau, Richard AU - Peter, Jonny AU - Theron, Grant AU - Calligaro, Greg AU - Allwood, Brian AU - Symons, Greg AU - Khalfey, Hoosain AU - Ntombenhle, Gina AU - Govender, Ureshnie AU - Binder, Anke AU - van Zyl-Smit, Richard AU - Dheda, Keertan AB - Background: The accuracy of currently available same-day diagnostic tools (smear microscopy and conventional nucleic acid amplification tests) for pleural tuberculosis (TB) is sub-optimal. Newer technologies may offer improved detection. Methods: Smear-microscopy, adenosine deaminase (ADA), interferon gamma (IFN-γ), and Xpert MTB/RIF [using an unprocessed (1 ml) and centrifuged (~20 ml) sample] test accuracy was evaluated in pleural fluid from 103 consecutive patients with suspected pleural TB. Culture for M.tuberculosis and/or histopathology (pleural biopsy) served as the reference standard. Patients were followed prospectively to determine their diagnostic categorisation. Results: Of 93 evaluable participants, 40 had definite-TB (reference positive), 5 probable-TB (not definite but treated for TB) and 48 non-TB (culture and histology negative, and not treated for TB). Xpert MTB/RIF sensitivity and specificity (95% CI) was 22.5% (12.4 - 37.6) and 98% (89.2 - 99.7), respectively, and centrifugation did not improve sensitivity (23.7%). The Xpert MTB/RIF internal positive control showed no evidence of inhibition. Biomarker specific sensitivity, specificity, PPV, and NPVs were: ADA (48.85 IU/L; rule-in cut-point) 55.3% (39.8 - 69.9), 95.2% (83.9 - 98.7), 91.4 (73.4 - 95.4), 69.7% (56.7 - 80.1); ADA (30 IU/L; clinically used cut-point) 79% (63.7 - 89), 92.7% (80.6 - 97.5), 91.0 (73.4 - 95.4), 82.7% (69.3 - 90.1); and IFN-γ (107.7 pg/ml; rule-in cut-point) 92.5% (80.2 - 97.5), 95.9% (86.1 - 98.9), 94.9% (83.2 - 98.6), 93.9% (83.5 - 97.9), respectively (IFN-γ sensitivity and NPV better than Xpert [p < 0.05] and rule-in ADA [p < 0.05]). Conclusion: The usefulness of Xpert MTB/RIF to diagnose pleural TB is limited by its poor sensitivity. IFN-γ is an excellent rule-in test and, compared to ADA, has significantly better sensitivity and rule-out value in a TB-endemic setting. DA - 2014-04-08 DB - OpenUCT DO - 10.1186/1471-2466-14-58 DP - University of Cape Town J1 - BMC Pulmonary Medicine LK - https://open.uct.ac.za PB - University of Cape Town PY - 2014 SM - 1471-2466 T1 - Comparison of same day diagnostic tools including Gene Xpert and unstimulated IFN-γ for the evaluation of pleural tuberculosis: a prospective cohort study TI - Comparison of same day diagnostic tools including Gene Xpert and unstimulated IFN-γ for the evaluation of pleural tuberculosis: a prospective cohort study UR - http://hdl.handle.net/11427/12334 ER - en_ZA


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