Cargando…

Diagnostic Accuracy of Lateral Flow Urine LAM Assay for TB Screening of Adults with Advanced Immunosuppression Attending Routine HIV Care in South Africa

BACKGROUND: We assessed the diagnostic accuracy of Determine TB-LAM (LF-LAM) to screen for tuberculosis among ambulatory adults established in HIV care in South Africa. METHODS: A systematic sample of adults attending for HIV care, regardless of symptomatology, were enrolled in the XPHACTOR study, w...

Descripción completa

Detalles Bibliográficos
Autores principales: Hanifa, Yasmeen, Fielding, Katherine L., Chihota, Violet N., Adonis, Lungiswa, Charalambous, Salome, Karstaedt, Alan, McCarthy, Kerrigan, Nicol, Mark P., Ndlovu, Nontobeko T., Sahid, Faieza, Churchyard, Gavin J., Grant, Alison D.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4896615/
https://www.ncbi.nlm.nih.gov/pubmed/27271432
http://dx.doi.org/10.1371/journal.pone.0156866
_version_ 1782436032663257088
author Hanifa, Yasmeen
Fielding, Katherine L.
Chihota, Violet N.
Adonis, Lungiswa
Charalambous, Salome
Karstaedt, Alan
McCarthy, Kerrigan
Nicol, Mark P.
Ndlovu, Nontobeko T.
Sahid, Faieza
Churchyard, Gavin J.
Grant, Alison D.
author_facet Hanifa, Yasmeen
Fielding, Katherine L.
Chihota, Violet N.
Adonis, Lungiswa
Charalambous, Salome
Karstaedt, Alan
McCarthy, Kerrigan
Nicol, Mark P.
Ndlovu, Nontobeko T.
Sahid, Faieza
Churchyard, Gavin J.
Grant, Alison D.
author_sort Hanifa, Yasmeen
collection PubMed
description BACKGROUND: We assessed the diagnostic accuracy of Determine TB-LAM (LF-LAM) to screen for tuberculosis among ambulatory adults established in HIV care in South Africa. METHODS: A systematic sample of adults attending for HIV care, regardless of symptomatology, were enrolled in the XPHACTOR study, which tested a novel algorithm for prioritising investigation with Xpert MTB/RIF. In this substudy, restricted to participants with enrolment CD4<200x10(6)/l, urine was stored at enrolment for later testing with LF-LAM. Sputum was sent for immediate Xpert MTB/RIF if any of: current cough, fever ≥3 weeks, body mass index (BMI)<18.5kg/m(2), CD4<100x10(6)/l (or <200x10(6)/l if pre-ART), weight loss ≥10% or strong clinical suspicion were present; otherwise, sputum was stored for Xpert testing at study completion. Participants were reviewed monthly, with reinvestigation if indicated, to 3 months, when sputum and blood were taken for mycobacterial culture. We defined tuberculosis as “confirmed” if Xpert, line probe assay or culture for M. tuberculosis within six months of enrolment were positive, and “clinical” if tuberculosis treatment started without microbiological confirmation. RESULTS: Amongst 424 participants, 61% were female and 57% were taking ART (median duration 22 months); median age, CD4 and BMI were 39 years, 111x10(6)/l, and 23 kg/m(2). 56/424 (13%) participants had tuberculosis (40 confirmed, 16 clinical). 24/424 (5.7%) vs. 8/424 (1.9%) were LAM-positive using grade 1 vs. grade 2 cut-off. Using grade 1 cut-off, sensitivity for confirmed TB (all clinical TB excluded) was 12.5% (95% CI 4.2%, 26.8%) and in CD4<100x10(6)/l vs. CD4 ≥100x10(6)/l was 16.7% (95% CI 4.7%, 37.4%) vs. 6.3% (95% CI 0.2%, 30.2%). Specificity was >95% irrespective of diagnostic reference standard, CD4 stratum, or whether grade 1 or grade 2 cut-off was used. CONCLUSION: Sensitivity of LF-LAM is too low to recommend as part of intensified case finding in ambulatory patients established in HIV care.
format Online
Article
Text
id pubmed-4896615
institution National Center for Biotechnology Information
language English
publishDate 2016
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-48966152016-06-16 Diagnostic Accuracy of Lateral Flow Urine LAM Assay for TB Screening of Adults with Advanced Immunosuppression Attending Routine HIV Care in South Africa Hanifa, Yasmeen Fielding, Katherine L. Chihota, Violet N. Adonis, Lungiswa Charalambous, Salome Karstaedt, Alan McCarthy, Kerrigan Nicol, Mark P. Ndlovu, Nontobeko T. Sahid, Faieza Churchyard, Gavin J. Grant, Alison D. PLoS One Research Article BACKGROUND: We assessed the diagnostic accuracy of Determine TB-LAM (LF-LAM) to screen for tuberculosis among ambulatory adults established in HIV care in South Africa. METHODS: A systematic sample of adults attending for HIV care, regardless of symptomatology, were enrolled in the XPHACTOR study, which tested a novel algorithm for prioritising investigation with Xpert MTB/RIF. In this substudy, restricted to participants with enrolment CD4<200x10(6)/l, urine was stored at enrolment for later testing with LF-LAM. Sputum was sent for immediate Xpert MTB/RIF if any of: current cough, fever ≥3 weeks, body mass index (BMI)<18.5kg/m(2), CD4<100x10(6)/l (or <200x10(6)/l if pre-ART), weight loss ≥10% or strong clinical suspicion were present; otherwise, sputum was stored for Xpert testing at study completion. Participants were reviewed monthly, with reinvestigation if indicated, to 3 months, when sputum and blood were taken for mycobacterial culture. We defined tuberculosis as “confirmed” if Xpert, line probe assay or culture for M. tuberculosis within six months of enrolment were positive, and “clinical” if tuberculosis treatment started without microbiological confirmation. RESULTS: Amongst 424 participants, 61% were female and 57% were taking ART (median duration 22 months); median age, CD4 and BMI were 39 years, 111x10(6)/l, and 23 kg/m(2). 56/424 (13%) participants had tuberculosis (40 confirmed, 16 clinical). 24/424 (5.7%) vs. 8/424 (1.9%) were LAM-positive using grade 1 vs. grade 2 cut-off. Using grade 1 cut-off, sensitivity for confirmed TB (all clinical TB excluded) was 12.5% (95% CI 4.2%, 26.8%) and in CD4<100x10(6)/l vs. CD4 ≥100x10(6)/l was 16.7% (95% CI 4.7%, 37.4%) vs. 6.3% (95% CI 0.2%, 30.2%). Specificity was >95% irrespective of diagnostic reference standard, CD4 stratum, or whether grade 1 or grade 2 cut-off was used. CONCLUSION: Sensitivity of LF-LAM is too low to recommend as part of intensified case finding in ambulatory patients established in HIV care. Public Library of Science 2016-06-07 /pmc/articles/PMC4896615/ /pubmed/27271432 http://dx.doi.org/10.1371/journal.pone.0156866 Text en © 2016 Hanifa et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Hanifa, Yasmeen
Fielding, Katherine L.
Chihota, Violet N.
Adonis, Lungiswa
Charalambous, Salome
Karstaedt, Alan
McCarthy, Kerrigan
Nicol, Mark P.
Ndlovu, Nontobeko T.
Sahid, Faieza
Churchyard, Gavin J.
Grant, Alison D.
Diagnostic Accuracy of Lateral Flow Urine LAM Assay for TB Screening of Adults with Advanced Immunosuppression Attending Routine HIV Care in South Africa
title Diagnostic Accuracy of Lateral Flow Urine LAM Assay for TB Screening of Adults with Advanced Immunosuppression Attending Routine HIV Care in South Africa
title_full Diagnostic Accuracy of Lateral Flow Urine LAM Assay for TB Screening of Adults with Advanced Immunosuppression Attending Routine HIV Care in South Africa
title_fullStr Diagnostic Accuracy of Lateral Flow Urine LAM Assay for TB Screening of Adults with Advanced Immunosuppression Attending Routine HIV Care in South Africa
title_full_unstemmed Diagnostic Accuracy of Lateral Flow Urine LAM Assay for TB Screening of Adults with Advanced Immunosuppression Attending Routine HIV Care in South Africa
title_short Diagnostic Accuracy of Lateral Flow Urine LAM Assay for TB Screening of Adults with Advanced Immunosuppression Attending Routine HIV Care in South Africa
title_sort diagnostic accuracy of lateral flow urine lam assay for tb screening of adults with advanced immunosuppression attending routine hiv care in south africa
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4896615/
https://www.ncbi.nlm.nih.gov/pubmed/27271432
http://dx.doi.org/10.1371/journal.pone.0156866
work_keys_str_mv AT hanifayasmeen diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica
AT fieldingkatherinel diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica
AT chihotavioletn diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica
AT adonislungiswa diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica
AT charalamboussalome diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica
AT karstaedtalan diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica
AT mccarthykerrigan diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica
AT nicolmarkp diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica
AT ndlovunontobekot diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica
AT sahidfaieza diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica
AT churchyardgavinj diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica
AT grantalisond diagnosticaccuracyoflateralflowurinelamassayfortbscreeningofadultswithadvancedimmunosuppressionattendingroutinehivcareinsouthafrica