Test characteristics and potential impact of the urine LAM lateral flow assay in HIV-infected outpatients under investigation for TB and able to self-expectorate sputum for diagnostic testing
dc.contributor.author | Peter, Jonny | en_ZA |
dc.contributor.author | Theron, Grant | en_ZA |
dc.contributor.author | Chanda, Duncan | en_ZA |
dc.contributor.author | Clowes, Petra | en_ZA |
dc.contributor.author | Rachow, Andrea | en_ZA |
dc.contributor.author | Lesosky, Maia | en_ZA |
dc.contributor.author | Hoelscher, Michael | en_ZA |
dc.contributor.author | Mwaba, Peter | en_ZA |
dc.contributor.author | Pym, Alex | en_ZA |
dc.contributor.author | Dheda, Keertan | en_ZA |
dc.contributor.author | For the TB-NEAT team | en_ZA |
dc.date.accessioned | 2015-12-07T08:52:11Z | |
dc.date.available | 2015-12-07T08:52:11Z | |
dc.date.issued | 2015 | en_ZA |
dc.description.abstract | BACKGROUND: The commercially available urine LAM strip test, a point-of-care tuberculosis (TB) assay, requires evaluation in a primary care setting where it is most needed. There is currently inadequate data to guide implementation in TB and HIV-endemic settings. METHODS: Adult HIV-infected outpatients with suspected pulmonary TB able to self-expectorate sputum from four primary clinics in South Africa, Zambia and Tanzania underwent diagnostic evaluation [sputum smear microscopy, Xpert-MTB/RIF, and culture (reference standard)] as part of a prospective parent study. Urine LAM testing (grade-2 cut-point) was performed on archived samples. Performance characteristics of LAM alone or in combination with sputum--based diagnostics were evaluated. Potential impact on 2 and 6-month morbidity (TBscore), patient dropout rates, and prognosis (death/ loss to follow-up) were evaluated. RESULTS: Among 583 participants with suspected TB that were HIV-infected or refused testing, the overall LAM sensitivity (95 % CI; n/N) and in the CD4[less than or equal to]100 cells/mm 3 sub-group was 22.7 % (16.6-28.7; 41/181) and 30.4 % (17.1-43.7; 14/46), respectively. Overall specificity was 93.0 % (90.5-95.6; 361/388). Amongst culture-positive TB cases, adjunctive LAM testing did not improve the sensitivity of either sputum Xpert-MTB/RIF [78.2 % (69.8-86.7; 72/92) versus 76.1 % (67.4-84.8; 70/92), p=0.7] or smear-microscopy [56.2 % (45.9-66.5; 50/89) versus 43.8 % (33.5-54.1; 39/89), p=0.1). Clinic-based LAM, as an adjunct to either smear microscopy or Xpert MTB/RIF same-day testing, would neither have decreased patient dropout, nor increased same-day treatment initiation in this clinical setting where same-day chest radiography was available. LAM positivity was associated with 6-month lost-to-follow-up/death (AOR 4.4; p=0.002) but not TBscore (at baseline or change in TBscore 2-months post-treatment) (p=0.17). CONCLUSIONS: In African HIV-TB co-infected outpatients able to self-expectorate sputum LAM had limited sensitivity even at low CD4 counts, and offered no significant incremental diagnostic yield over Xpert-MTB/RIF or smear microscopy. In primary care clinics with chest radiography and where empiric TB treatment is common, LAM seems unlikely to improve rates of same-day treatment initiation and patient dropout, however, the ability of LAM to identify patients at high risk of death or lost-to-follow-up may offer important prognostic value. | en_ZA |
dc.identifier.apacitation | Peter, J., Theron, G., Chanda, D., Clowes, P., Rachow, A., Lesosky, M., ... (2015). Test characteristics and potential impact of the urine LAM lateral flow assay in HIV-infected outpatients under investigation for TB and able to self-expectorate sputum for diagnostic testing. <i>BMC Infectious Diseases</i>, http://hdl.handle.net/11427/15650 | en_ZA |
dc.identifier.chicagocitation | Peter, Jonny, Grant Theron, Duncan Chanda, Petra Clowes, Andrea Rachow, Maia Lesosky, Michael Hoelscher, et al "Test characteristics and potential impact of the urine LAM lateral flow assay in HIV-infected outpatients under investigation for TB and able to self-expectorate sputum for diagnostic testing." <i>BMC Infectious Diseases</i> (2015) http://hdl.handle.net/11427/15650 | en_ZA |
dc.identifier.citation | Peter, J., Theron, G., Chanda, D., Clowes, P., Rachow, A., Lesosky, M., ... & Dheda, K. (2015). Test characteristics and potential impact of the urine LAM lateral flow assay in HIV-infected outpatients under investigation for TB and able to self-expectorate sputum for diagnostic testing. BMC infectious diseases, 15(1), 262. | en_ZA |
dc.identifier.ris | TY - Journal Article AU - Peter, Jonny AU - Theron, Grant AU - Chanda, Duncan AU - Clowes, Petra AU - Rachow, Andrea AU - Lesosky, Maia AU - Hoelscher, Michael AU - Mwaba, Peter AU - Pym, Alex AU - Dheda, Keertan AU - For the TB-NEAT team AB - BACKGROUND: The commercially available urine LAM strip test, a point-of-care tuberculosis (TB) assay, requires evaluation in a primary care setting where it is most needed. There is currently inadequate data to guide implementation in TB and HIV-endemic settings. METHODS: Adult HIV-infected outpatients with suspected pulmonary TB able to self-expectorate sputum from four primary clinics in South Africa, Zambia and Tanzania underwent diagnostic evaluation [sputum smear microscopy, Xpert-MTB/RIF, and culture (reference standard)] as part of a prospective parent study. Urine LAM testing (grade-2 cut-point) was performed on archived samples. Performance characteristics of LAM alone or in combination with sputum--based diagnostics were evaluated. Potential impact on 2 and 6-month morbidity (TBscore), patient dropout rates, and prognosis (death/ loss to follow-up) were evaluated. RESULTS: Among 583 participants with suspected TB that were HIV-infected or refused testing, the overall LAM sensitivity (95 % CI; n/N) and in the CD4[less than or equal to]100 cells/mm 3 sub-group was 22.7 % (16.6-28.7; 41/181) and 30.4 % (17.1-43.7; 14/46), respectively. Overall specificity was 93.0 % (90.5-95.6; 361/388). Amongst culture-positive TB cases, adjunctive LAM testing did not improve the sensitivity of either sputum Xpert-MTB/RIF [78.2 % (69.8-86.7; 72/92) versus 76.1 % (67.4-84.8; 70/92), p=0.7] or smear-microscopy [56.2 % (45.9-66.5; 50/89) versus 43.8 % (33.5-54.1; 39/89), p=0.1). Clinic-based LAM, as an adjunct to either smear microscopy or Xpert MTB/RIF same-day testing, would neither have decreased patient dropout, nor increased same-day treatment initiation in this clinical setting where same-day chest radiography was available. LAM positivity was associated with 6-month lost-to-follow-up/death (AOR 4.4; p=0.002) but not TBscore (at baseline or change in TBscore 2-months post-treatment) (p=0.17). CONCLUSIONS: In African HIV-TB co-infected outpatients able to self-expectorate sputum LAM had limited sensitivity even at low CD4 counts, and offered no significant incremental diagnostic yield over Xpert-MTB/RIF or smear microscopy. In primary care clinics with chest radiography and where empiric TB treatment is common, LAM seems unlikely to improve rates of same-day treatment initiation and patient dropout, however, the ability of LAM to identify patients at high risk of death or lost-to-follow-up may offer important prognostic value. DA - 2015 DB - OpenUCT DO - 10.1186/s12879-015-0967-z DP - University of Cape Town J1 - BMC Infectious Diseases LK - https://open.uct.ac.za PB - University of Cape Town PY - 2015 T1 - Test characteristics and potential impact of the urine LAM lateral flow assay in HIV-infected outpatients under investigation for TB and able to self-expectorate sputum for diagnostic testing TI - Test characteristics and potential impact of the urine LAM lateral flow assay in HIV-infected outpatients under investigation for TB and able to self-expectorate sputum for diagnostic testing UR - http://hdl.handle.net/11427/15650 ER - | en_ZA |
dc.identifier.uri | http://hdl.handle.net/11427/15650 | |
dc.identifier.uri | http://dx.doi.org/10.1186/s12879-015-0967-z | |
dc.identifier.vancouvercitation | Peter J, Theron G, Chanda D, Clowes P, Rachow A, Lesosky M, et al. Test characteristics and potential impact of the urine LAM lateral flow assay in HIV-infected outpatients under investigation for TB and able to self-expectorate sputum for diagnostic testing. BMC Infectious Diseases. 2015; http://hdl.handle.net/11427/15650. | en_ZA |
dc.language.iso | eng | en_ZA |
dc.publisher | BioMed Central Ltd | en_ZA |
dc.publisher.department | Department of Medicine | en_ZA |
dc.publisher.faculty | Faculty of Health Sciences | en_ZA |
dc.publisher.institution | University of Cape Town | |
dc.rights | This is an Open Access article distributed under the terms of the Creative Commons Attribution License | en_ZA |
dc.rights.holder | 2015 Peter et al. | en_ZA |
dc.rights.uri | http://creativecommons.org/licenses/by/4.0 | en_ZA |
dc.source | BMC Infectious Diseases | en_ZA |
dc.source.uri | http://www.biomedcentral.com/bmcinfectdis/ | en_ZA |
dc.subject.other | Division of Pulmonology | en_ZA |
dc.title | Test characteristics and potential impact of the urine LAM lateral flow assay in HIV-infected outpatients under investigation for TB and able to self-expectorate sputum for diagnostic testing | en_ZA |
dc.type | Journal Article | en_ZA |
uct.type.filetype | Text | |
uct.type.filetype | Image | |
uct.type.publication | Research | en_ZA |
uct.type.resource | Article | en_ZA |
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