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1.
Lancet Microbe ; 5(5): e433-e441, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38461830

RESUMO

BACKGROUND: Despite increasing availability of rapid molecular tests for the diagnosis of tuberculosis in high-burden settings, many people with tuberculosis are undiagnosed. Reliance on sputum as the primary specimen for tuberculosis diagnostics contributes to this diagnostic gap. We evaluated the diagnostic accuracy and additive yield of a novel stool quantitative PCR (qPCR) assay for the diagnosis of tuberculosis in three countries in Africa with high tuberculosis burdens. METHODS: We undertook a prospective diagnostic accuracy study in Eswatini, Mozambique, and Tanzania from Sept 21, 2020, to Feb 2, 2023, to compare the diagnostic accuracy for tuberculosis of a novel stool qPCR test with the current diagnostic standard for Mycobacterium tuberculosis DNA detection from sputum and stool, Xpert-MTB/RIF Ultra (Xpert Ultra). Sputum, stool, and urine samples were provided by a cohort of participants, aged 10 years or older, diagnosed with tuberculosis. Participants with tuberculosis (cases) were enrolled within 72 h of treatment initiation for tuberculosis diagnosed clinically or following laboratory confirmation. Participants without tuberculosis (controls) consisted of household contacts of the cases who did not develop tuberculosis during a 6-month follow-up. The performance was compared with a robust composite microbiological reference standard (CMRS). FINDINGS: The cohort of adolescents and adults (n=408) included 268 participants with confirmed or clinical tuberculosis (cases), 147 (55%) of whom were living with HIV, and 140 participants (controls) without tuberculosis. The sensitivity of the novel stool qPCR was 93·7% (95% CI 87·4-97·4) compared with participants with detectable growth on M tuberculosis culture, and 88·1% (81·3-93·0) compared with sputum Xpert Ultra. The stool qPCR had an equivalent sensitivity as sputum Xpert Ultra (94·8%, 89·1-98·1) compared with culture. Compared with the CMRS, the sensitivity of the stool qPCR was higher than the current standard for tuberculosis diagnostics on stool, Xpert Ultra (80·4%, 73·4-86·2 vs 73·5%, 66·0-80·1; p=0·025 on paired comparison). The qPCR also identified 17-21% additional tuberculosis cases compared to sputum Xpert Ultra or sputum culture. In controls without tuberculosis, the specificity of the stool qPCR was 96·9% (92·2-99·1). INTERPRETATION: In this study, a novel qPCR for the diagnosis of tuberculosis from stool specimens had a higher accuracy in adolescents and adults than the current diagnostic PCR gold standard on stool, Xpert-MTB/RIF Ultra, and equivalent sensitivity to Xpert-MTB/RIF Ultra on sputum. FUNDING: National Institutes of Health (NIH) Allergy and Infectious Diseases, and NIH Fogarty International Center.


Assuntos
Fezes , Mycobacterium tuberculosis , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Escarro , Tuberculose , Humanos , Adolescente , Fezes/microbiologia , Fezes/química , Adulto , Estudos Prospectivos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Feminino , Masculino , Reação em Cadeia da Polimerase em Tempo Real/métodos , Adulto Jovem , Tuberculose/diagnóstico , Tuberculose/microbiologia , Tuberculose/urina , Escarro/microbiologia , Pessoa de Meia-Idade , Criança , Tanzânia/epidemiologia , DNA Bacteriano/análise , Moçambique/epidemiologia
3.
Lancet Glob Health ; 11(1): e126-e135, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36521944

RESUMO

BACKGROUND: Development of rapid biomarker-based tests that can diagnose tuberculosis using non-sputum samples is a priority for tuberculosis control. We aimed to compare the diagnostic accuracy of the novel Fujifilm SILVAMP TB LAM (FujiLAM) assay with the WHO-recommended Alere Determine TB-LAM Ag test (AlereLAM) using urine samples from HIV-positive patients. METHODS: We did a diagnostic accuracy study at five outpatient public health facilities in Uganda, Kenya, Mozambique, and South Africa. Eligible patients were ambulatory HIV-positive individuals (aged ≥15 years) with symptoms of tuberculosis irrespective of their CD4 T-cell count (group 1), and asymptomatic patients with advanced HIV disease (CD4 count <200 cells per µL, or HIV clinical stage 3 or 4; group 2). All participants underwent clinical examination, chest x-ray, and blood sampling, and were requested to provide a fresh urine sample, and two sputum samples. FujiLAM and AlereLAM urine assays, Xpert MTB/RIF Ultra assay on sputum or urine, sputum culture for Mycobacterium tuberculosis, and CD4 count were systematically carried out for all patients. Sensitivity and specificity of FujiLAM and AlereLAM were evaluated against microbiological and composite reference standards. FINDINGS: Between Aug 24, 2020 and Sept 21, 2021, 1575 patients (823 [52·3%] women) were included in the study: 1031 patients in group 1 and 544 patients in group 2. Tuberculosis was microbiologically confirmed in 96 (9·4%) of 1022 patients in group 1 and 18 (3·3%) of 542 patients in group 2. Using the microbiological reference standard, FujiLAM sensitivity was 60% (95% CI 51-69) and AlereLAM sensitivity was 40% (31-49; p<0·001). Among patients with CD4 counts of less than 200 cells per µL, FujiLAM sensitivity was 69% (57-79) and AlereLAM sensitivity was 52% (40-64; p=0·0218). Among patients with CD4 counts of 200 cells per µL or higher, FujiLAM sensitivity was 47% (34-61) and AlereLAM sensitivity was 24% (14-38; p=0·0116). Using the microbiological reference standard, FujiLAM specificity was 87% (95% CI 85-89) and AlereLAM specificity was 86% (95 CI 84-88; p=0·941). FujiLAM sensitivity varied by lot number from 48% (34-62) to 76% (57-89) and specificity from 77% (72-81) to 98% (93-99). INTERPRETATION: Next-generation, higher sensitivity urine-lipoarabinomannan assays are potentially promising tests that allow rapid tuberculosis diagnosis at the point of care for HIV-positive patients. However, the variability in accuracy between FujiLAM lot numbers needs to be addressed before clinical use. FUNDING: ANRS and Médecins Sans Frontières.


Assuntos
Infecções por HIV , Mycobacterium tuberculosis , Tuberculose , Humanos , Feminino , Masculino , Tuberculose/diagnóstico , Tuberculose/urina , Contagem de Linfócito CD4 , Infecções por HIV/complicações , Infecções por HIV/diagnóstico , Sensibilidade e Especificidade , Lipopolissacarídeos/urina , População Africana , África do Sul
4.
J Clin Microbiol ; 60(8): e0043122, 2022 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-35913145

RESUMO

Testing for mycobacterial lipoarabinomannan (LAM) in urine is a practical but insensitive alternative to sputum testing to diagnose tuberculosis (TB) in people with HIV (PWH). Here, we evaluated urine LAM testing alongside PCR-based tests for Mycobacterium tuberculosis (MTB) DNA in tongue swabs. We hypothesized that the two nonsputum samples would deliver complementary, not redundant, results. The study included 131 South African patients of whom 64 (48.1%) were confirmed to have TB by GeneXpert MTB/RIF Ultra (Xpert Ultra) or culture analysis of sputum. A total of 120 patients (91.6%) were coinfected with HIV and 130 yielded a valid urine LAM result (Alere DETERMINE LAM Ag). Tongue swab samples were tested by IS6110-targeted qPCR with a quantification cycle (Cq) cutoff of 32. Relative to reference sputum testing (TB culture and Xpert Ultra), combined urine LAM and oral swab testing (either sample positive) was significantly more sensitive than either nonsputum sample alone (57% sensitivity for combined testing versus 35% and 39% sensitivity for urine LAM and tongue swabs; P = 0.01 and 0.04, respectively). Specificity of combined testing (neither sample positive) was 97%. On average, tongue swab-positive participants had higher sputum signal strength than urine-LAM positive participants, as measured by sputum Xpert Ultra Cq value (P = 0.037). A subset of tongue swabs (N = 18) was also tested by using Xpert Ultra, which reproduced true positive and true negative IS6110 qPCR results and resolved the two false-positive tongue swabs. With further development, tongue swabs and urine may feasibly serve as complementary nonsputum samples for diagnosis of TB in PWH.


Assuntos
Infecções por HIV , Mycobacterium tuberculosis , Tuberculose , Técnicas e Procedimentos Diagnósticos , Infecções por HIV/complicações , Humanos , Lipopolissacarídeos/urina , Mycobacterium tuberculosis/genética , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Escarro/microbiologia , Tuberculose/diagnóstico , Tuberculose/urina
5.
Int J Tuberc Lung Dis ; 26(9): 835-841, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35996279

RESUMO

INTRODUCTION: Since 2015 (updated in 2019), the WHO has recommended to include the commercial lateral flow urine lipoarabinomannan TB test (LF-LAM), AlereLAM, in the diagnostic toolkit for severely ill people living with HIV.METHODS: To assess the current use and barriers to the implementation of the test, we conducted an electronic survey among national focal points and managers of TB and HIV programmes in the 53 Member States of the WHO European Region and a European network of clinicians working in TB and HIV medicine.RESULTS: In all, 45 individual responses (37 countries) were received from programme managers and focal points and 17 responses (14 countries) from clinicians. Only eight countries reported adopting LF-LAM policies, with only four currently using the AlereLAM (Armenia, Belarus, Ukraine and Uzbekistan). The most commonly reported barriers to implementing the test were the small number of eligible patients (with HIV-TB co-infections), the test not being included in the TB or HIV programme´s mandate and lack of budget allocation.CONCLUSION: Consistent with findings from high TB burden countries in Africa and Asia, the survey demonstrated that uptake of AlereLAM is almost non-existent. Addressing the identified barriers and the intrinsic limitations of the test could help to increase the use of the test.


Assuntos
Lipopolissacarídeos , Urinálise , Ásia , Europa (Continente) , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Humanos , Lipopolissacarídeos/urina , Sensibilidade e Especificidade , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Tuberculose/urina
6.
Int J Infect Dis ; 122: 415-419, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35690363

RESUMO

BACKGROUND: The diagnosis of extrapulmonary tuberculosis (EPTB) in patients with HIV remains a challenge for clinicians. The World Health Organization recommends the detection of lipoarabinomannan (LAM) for diagnosing pulmonary tuberculosis in patients with HIV. A new generation of urine LAM tests (FujiLAM®) is available. However, studies regarding its accuracy are limited. OBJECTIVE: This study aimed to evaluate the accuracy of urine LAM tests using FujiLAM® for diagnosing EPTB in patients with HIV. METHODS: A cross-sectional study using urine samples of patients at Cipto Mangunkusumo Hospital, Indonesia, was performed from January 2020 to December 2020. Fresh urine was applied to the FujiLAM®. Patients were grouped into definitive, probable, and non-TB groups. The diagnostic accuracy of the urine LAM test was compared with other Mycobacterium tuberculosis specimen gold standard tests. RESULTS: Among 62 patients, 16 patients (25.8%) had definitive diagnosis of EPTB. Among those with definitive TB, an urine LAM test yielded a sensitivity of 75% (95% confidence interval [CI]: 47.62-92.73%) and specificity of 73.91% (95% CI: 87-85.73%). Meanwhile, compared with all diagnostic tests (definite + probable TB), FujiLAM® had a sensitivity value of 61% (95% CI 43.36-76.86%) and a specificity value of 92.31% (95% CI 74.87-99.05%). CONCLUSION: The FujiLAM® test is a feasible method for diagnosing EPTB in patients with HIV.


Assuntos
Infecções por HIV , Tuberculose , Adulto , Estudos Transversais , Infecções por HIV/complicações , Infecções por HIV/diagnóstico , Infecções por HIV/microbiologia , Humanos , Lipopolissacarídeos/urina , Sensibilidade e Especificidade , Tuberculose/diagnóstico , Tuberculose/urina
7.
J Biol Chem ; 298(3): 101678, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35122792

RESUMO

Detecting the mycobacterial glycolipid lipoarabinomannan (LAM) in urine by anti-LAM antibodies fills a gap in the diagnostic armamentarium of much needed simple rapid tests for tuberculosis, but lacks high sensitivity in all patient groups. A better understanding of LAM structure from clinically relevant strains may allow improvements in diagnostic performance. De et al. have recently determined the structures of LAM from three epidemiologically important lineages of Mycobacterium tuberculosis and probed their interaction with an anti-LAM monoclonal antibody. Their results not only identify a series of tailoring modifications that impact antibody binding but also provide a roadmap for improving U-LAM-based diagnostics.


Assuntos
Lipopolissacarídeos , Mycobacterium tuberculosis , Tuberculose , Humanos , Lipopolissacarídeos/química , Lipopolissacarídeos/urina , Mycobacterium tuberculosis/química , Sensibilidade e Especificidade , Tuberculose/diagnóstico , Tuberculose/microbiologia , Tuberculose/urina
8.
J Clin Lab Anal ; 36(2): e24238, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35034374

RESUMO

OBJECTIVES: Even today, tuberculosis (TB) remains a leading public health problem; yet, the current diagnostic methods still have a few shortcomings. Lipoarabinomannan (LAM) provides an opportunity for TB diagnosis, and urine LAM detection seems to have a promising and widely applicable prospect. DESIGN OR METHODS: Four databases were systematically searched for eligible studies, and the quality of the studies was evaluated using the quality assessment of diagnostic accuracy studies-2 (QUADAS-2). Graphs and tables were created to show sensitivity, specificity, likelihood ratios, diagnostic odds ratio (DOR), the area under the curve (AUC), and so on. RESULTS: Based on the included 67 studies, the pooled sensitivity of urine LAM was 48% and specificity was 89%. In the subgroup analyses, the FujiLAM test had higher sensitivity (69%) and specificity (92%). Furthermore, among patients infected with human immunodeficiency virus (HIV), 50% of TB patients were diagnosed using a urine LAM test. Besides, the CD4+ cell count was inversely proportional to the sensitivity. CONCLUSIONS: Urine LAM is a promising diagnostic test for TB, particularly using the FujiLAM in HIV-infected adults whose CD4+ cell count is ≤100 per µl. Besides, the urine LAM test shows various sensitivities and specificities in different subgroups in terms of age, HIV infection status, CD4+ cell count, and testing method.


Assuntos
Lipopolissacarídeos/urina , Tuberculose/diagnóstico , Adulto , Contagem de Linfócito CD4 , Criança , Infecções por HIV/complicações , Humanos , Mycobacterium tuberculosis , Sensibilidade e Especificidade , Tuberculose/complicações , Tuberculose/urina
9.
PLoS One ; 16(7): e0254156, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34310609

RESUMO

Detection of tuberculosis at the point-of-care (POC) is limited by the low sensitivity of current commercially available tests. We describe a diagnostic accuracy field evaluation of a prototype urine Tuberculosis Lipoarabinomannan Lateral Flow Assay (TB-LAM LFA) in both HIV-positive and HIV-negative patients using fresh samples with sensitivity and specificity as the measures of accuracy. This prototype combines a proprietary concentration system with a sensitive LFA. In a prospective study of 292 patients with suspected pulmonary tuberculosis in Uganda, the clinical sensitivity and specificity was compared against a microbiological reference standard including sputum Xpert MTB/RIF Ultra and solid and liquid culture. TB-LAM LFA had an overall sensitivity of 60% (95%CI 51-69%) and specificity of 80% (95%CI 73-85%). When comparing HIV-positive (N = 86) and HIV-negative (N = 206) patients, there was no significant difference in sensitivity (sensitivity difference 8%, 95%CI -11% to +24%, p = 0.4351) or specificity (specificity difference -9%, 95%CI -24% to +4%, p = 0.2051). Compared to the commercially available Alere Determine TB-LAM Ag test, the TB-LAM LFA prototype had improved sensitivity in both HIV-negative (difference 49%, 95%CI 37% to 59%, p<0.0001) and HIV-positive patients with CD4+ T-cell counts >200cells/µL (difference 59%, 95%CI 32% to 75%, p = 0.0009). This report is the first to show improved performance of a urine TB LAM test for HIV-negative patients in a high TB burden setting. We also offer potential assay refinement solutions that may further improve sensitivity and specificity.


Assuntos
Infecções por HIV/urina , Soropositividade para HIV/urina , Lipopolissacarídeos/urina , Tuberculose/urina , Adulto , Feminino , HIV/patogenicidade , Infecções por HIV/complicações , Infecções por HIV/microbiologia , Infecções por HIV/virologia , Soropositividade para HIV/microbiologia , Soropositividade para HIV/virologia , Humanos , Masculino , Testes Imediatos , Escarro/microbiologia , Escarro/virologia , Tuberculose/complicações , Tuberculose/microbiologia , Tuberculose/virologia , Uganda/epidemiologia , Adulto Jovem
10.
IUBMB Life ; 73(8): 1073-1083, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34048129

RESUMO

Tuberculosis (TB) is caused by Mycobacterium tuberculosis and is one of the primary causes of death worldwide. Rapid and accurate diagnosis of TB is one of the most direct means to reduce the incidence of TB. In this study, urinary proteomic profiling of TB patients and non-TB individual controls (HCs) was performed, and differentially expressed urinary proteins between TB and HCs were compared and exclusively expressed proteins in TB patients were selected to establish a clinically useful disease marker panel. In total, these top 11 targeted proteins with 265 peptides were scheduled for multiple reaction monitoring validation analysis by using urine samples from 52 TB patients and 52 HCs. The result demonstrated that a three-protein combination out of the five-protein panel (namely P22352, Q9P121, P15151, Q13291, and Q8NDA2) exhibited sensitivity rate of 82.7% in the diagnosis of TB. Furthermore, the three-protein combination could differentiate TB from the latent tuberculosis (LTB) effectively, which exhibited specificity rate of 92.3% for the diagnosis of TB from the LTB category. Although more numbers of clinical samples are required for further verification, the results provided preliminary evidence that this "three-protein combination" out of the five-protein panel could probably be a novel TB diagnostic biomarker in clinical application.


Assuntos
Biomarcadores/urina , Proteinúria/diagnóstico , Tuberculose/urina , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Tuberculose Latente/diagnóstico , Tuberculose Latente/urina , Masculino , Peso Molecular , Proteínas/química , Proteínas/metabolismo , Proteômica/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas em Tandem , Tuberculose/diagnóstico , Urinálise/métodos
11.
PLoS One ; 16(5): e0250933, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33951082

RESUMO

BACKGROUND: Tuberculosis (TB) is a serious co-morbidity among children with severe acute malnutrition (SAM) and TB diagnosis remains particularly challenging in the very young. We explored whether, in a low HIV-prevalence setting, the detection of mycobacterial lipoarabinomannan (LAM) antigen in urine may assist TB diagnosis in SAM children, a pediatric population currently not included in LAM-testing recommendations. To that end, we assessed LAM test-positivity among SAM children with and without signs or symptoms of TB. METHODS: A cross-sectional assessment (February 2016-August 2017) included children <5 years with SAM from an Intensive-Therapeutic-Feeding-Centre in Madaoua, Niger. Group 1: children with signs or symptoms suggestive of TB. Group 2: children without any sign or symptom of TB. Urine-specimens were subjected to DetermineTM TB-LAM lateral-flow-test (using a 4-grade intensity scale for positives). LAM-results were used for study purposes and not for patient management. Programmatic TB-diagnosis was primarily based on patients' clinical symptoms and TB contact history with no systematic access to X-ray or microbiological reference testing. RESULTS: 102 (Group 1) and 100 children (Group 2) were included (median age 18 months, 59.4% male, 1.0% HIV-positive). In Group 1, 22 (21.6%) children were started on TB-treatment (probable TB) and none of the children in Group 2. LAM-positivity was 52.0% (53/102) and 37.0% (37/100) in Group 1 and 2, respectively. Low-intensity (Grade 1) LAM test-positivity was similarly high in both Groups (37.3% and 36.0%, respectively), while Grade 2 or 3-positives were mainly detected in Group 1 (Group 1: 14.7%, Group 2: 1.0%, p<0.001). When considering only Grades >1 as positive, LAM-testing detected 22.7% (95%CI: 7.8, 45.4) among probable TB cases, while 99% (95%CI: 94.6, 99.9) of unlikely TB cases (Group 2) tested negative. CONCLUSION: These findings suggest the potential utility of LAM urine testing in HIV-negative children with SAM. Determine LAM-positivity with Grades >1 may identify HIV-negative SAM children that are eligible for rapid TB-treatment initiation, though low-intensity (Grade 1) LAM-positive results may not be helpful in this way. Further studies in this specific pediatric population are warranted, including evaluations of new generation LAM tests.


Assuntos
Lipopolissacarídeos/urina , Desnutrição Aguda Grave/diagnóstico , Desnutrição Aguda Grave/urina , Tuberculose/diagnóstico , Tuberculose/urina , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Testes Imunológicos/métodos , Lactente , Masculino , Níger , Urinálise/métodos
12.
Sci Rep ; 11(1): 2922, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33536495

RESUMO

Our study sought to determine whether urine lipoarabinomannan (LAM) could be validated in a sample cohort that consisted mainly of HIV uninfected individuals that presented with tuberculosis symptoms. We evaluated two tests developed in our laboratory, and used them on clinical samples from Lima, Peru where incidence of HIV is low. ELISA analysis was performed on 160 samples (from 140 adult culture-confirmed TB cases and 20 symptomatic TB-negative child controls) using 100 µL of urine after pretreatment with Proteinase K. Two different mouse monoclonal antibodies-CS35 and CHCS9-08 were used individually for capture of urine LAM. Among cases, optical density (OD450) values had a positive association with higher bacillary loads. The 20 controls had negative values (below the limit of detection). The assay correctly identified all samples (97-100% accuracy confidence interval). For an alternate validation of the ELISA results, we analyzed all 160 urine samples using an antibody independent chemoanalytical approach. Samples were called positive only when LAM surrogates-tuberculostearic acid (TBSA) and D-arabinose (D-ara)-were found to be present in similar amounts. All TB cases, including the 40 with a negative sputum smear had LAM in detectable quantities in urine. None of the controls had detectable amounts of LAM. Our study shows that urinary LAM detection is feasible in HIV uninfected, smear negative TB patients.


Assuntos
Lipopolissacarídeos/urina , Mycobacterium tuberculosis/isolamento & purificação , Manejo de Espécimes/métodos , Tuberculose/diagnóstico , Adulto , Criança , Estudos de Coortes , Estudos de Viabilidade , Humanos , Testes Imunológicos/métodos , Limite de Detecção , Espectrometria de Massas , Peru , Escarro/microbiologia , Tuberculose/microbiologia , Tuberculose/urina
13.
PLoS One ; 16(2): e0247851, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33635932

RESUMO

Urine cell-free DNA (cfDNA) is a valuable non-invasive biomarker with broad potential clinical applications, but there is no consensus on its optimal pre-analytical methodology, including the DNA extraction step. Due to its short length (majority of fragments <100 bp) and low concentration (ng/mL), urine cfDNA is not efficiently recovered by conventional silica-based extraction methods. To maximize sensitivity of urine cfDNA assays, we developed an ultrasensitive hybridization method that uses sequence-specific oligonucleotide capture probes immobilized on magnetic beads to improve extraction of short cfDNA from large-volume urine samples. Our hybridization method recovers near 100% (95% CI: 82.6-117.6%) of target-specific DNA from 10 mL urine, independent of fragment length (25-150 bp), and has a limit of detection of ≤5 copies of double-stranded DNA (0.5 copies/mL). Pairing hybridization with an ultrashort qPCR design, we can efficiently capture and amplify fragments as short as 25 bp. Our method enables amplification of cfDNA from 10 mL urine in a single qPCR well, tolerates variation in sample composition, and effectively removes non-target DNA. Our hybridization protocol improves upon both existing silica-based urine cfDNA extraction methods and previous hybridization-based sample preparation protocols. Two key innovations contribute to the strong performance of our method: a two-probe system enabling recovery of both strands of double-stranded DNA and dual biotinylated capture probes, which ensure consistent, high recovery by facilitating optimal probe density on the bead surface, improving thermostability of the probe-bead linkage, and eliminating interference by endogenous biotin. We originally designed the hybridization method for tuberculosis diagnosis from urine cfDNA, but expect that it will be versatile across urine cfDNA targets, and may be useful for other cfDNA sample types and applications beyond cfDNA. To make our hybridization method accessible to new users, we present a detailed protocol and straightforward guidelines for designing new capture probes.


Assuntos
Ácidos Nucleicos Livres/genética , Ácidos Nucleicos Livres/urina , Variações do Número de Cópias de DNA , DNA Bacteriano/genética , DNA Bacteriano/urina , Limite de Detecção , Mycobacterium tuberculosis/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Tuberculose/urina , Biomarcadores/urina , Estudos de Viabilidade , Humanos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tuberculose/microbiologia , Coleta de Urina/métodos
14.
Brasília; CONITEC; fev. 2021.
Não convencional em Português | BRISA/RedTESA | ID: biblio-1255178

RESUMO

INTRODUÇÃO: As PVHIV estão mais propensas a desenvolver TB quando comparadas a população geral. Embora tenha havido um aumento das notificações de TB associada ao HIV nos últimos anos, em 2016, elas corresponderam apenas a 46% do total estimado pela Organização Mundial da Saúde (OMS), evidenciando as lacunas que ainda existentes na detecção, tratamento e acompanhamento adequado dessas pessoas. Testes rápidos baseados na detecção do antígeno lipoarabinomanano micobacteriano (LAM) na urina surgiram como possíveis alternativas para rastreamento e diagnóstico durante atendimento de PVHIV com suspeita de TB por ser mais fácil coletar e armazenar a urina, reduzir os riscos de infecção associados à coleta de escarro e com liberação rápida de resultados. PERGUNTA: O uso do teste de fluxo lateral para detecção de lipoarabinomanano em urina (LF ­ LAM) é eficaz e preciso no diagnóstico de TB ativa em adultos HIV positivos que apresentam sinais e sintomas sugestivos de TB? TECNOLOGIA: Teste de fluxo lateral para detecção de lipoarabinomanano em urina (LF - LAM). EVIDÊNCIAS CIENTÍFICAS: Foram incluídos para análise 16 (dezesseis) estudos, sendo 11 (onze) do tipo coortes e 5 (cinco) transversais. A avaliação das evidências mostrou aumento da sensibilidade do LF-LAM nos pacientes mais doentes, principalmente entre os pacientes com baixa contagem de CD4+. A sensibilidade e especificidade combinadas de LF-LAM em pacientes com limiares de CD4+ ≤ 100 células/µL foram de 55,4% e 87%, respectivamente. As sensibilidades e especificidades combinadas de LF-LAM na população HIV positiva geral, graus 1 e 2 foram 43,6%, 88,2%, 41,9% e 92%, respectivamente. EVIDÊNCIAS ECONÔMICAS: Um modelo de arvore de Markov foi adaptado para analisar a razão de custo-efetividade (ICER) do LF-LAM em relação as alternativas para diagnóstico de TB em PVHIV. Observamos que o ICER por DALY salvo usando os testes TRM-TB (teste rápido molecular de TB) e LF-LAM/TRM-TB versus o protocolo padrão foram de R$4.905,04 e R$2.815,92, respectivamente. ANÁLISE DE IMPACTO ORÇAMENTÁRIO: O impacto orçamentário incremental (IOI) calculado pelo método epidemiológico estimou um gasto de R$2,5 milhões no primeiro ano e de R$ 4,8 milhões no quinto ano de incorporação do LF-LAM, enquanto pelo método de demanda aferida observamos uma estimativa de custos que variou de R$ 230 mil a R$ 337 mil no horizonte de cinco anos de análise (2021-2025). CONSIDERAÇÕES GERAIS: Dada a necessidade de rápida exclusão de TB nesse subgrupo de pacientes (PVHIV) devido ao alto risco de mortalidade e ao fato de o LF-LAM não exigir a coleta de escarro, recomendações internacionais sugerem que esse subgrupo de pacientes possa se beneficiar dos testes de LF-LAM. RECOMENDAÇÃO PRELIMINAR DA CONITEC: Diante do exposto, a Conitec, em sua 92ª reunião ordinária, realizada no dia 05 de novembro de 2020, deliberou que a matéria fosse disponibilizada em consulta pública com recomendação preliminar favorável à incorporação no SUS do teste de lipoarabinomanano de fluxo lateral na urina (LF-LAM) para rastreamento e diagnóstico de TB ativa em PVHIV. De acordo com o relatório apresentado, o LF-LAM foi mais custo-efetivo quando comparado com o TRM-TB. Também foi pontuado que a parte logística, em caso de incorporação, seria realizada de forma centralizada, e que a rede laboratorial em que os testes seriam empregados é aquela atualmente disponível para atendimento de pacientes com HIV/AIDS. Já a capacitação dos profissionais que realizarão o teste seria feita pelo MS, por meio do TELELAB. A matéria foi disponibilizada em consulta pública. CONSULTA PÚBLICA: A Consulta Pública nº 65/2020 foi realizada entre os dias 04/12/2020 a 23/12/2020. Foram recebidas 18 contribuições, sendo 07 pelo formulário para contribuições técnico-científicas e 11 pelo formulário para contribuições sobre experiência ou opinião de pacientes, familiares, amigos ou cuidadores de pacientes, profissionais de saúde ou pessoas interessadas no tema. Todas as contribuições concordaram com a recomendação preliminar da Conitec. No entanto, dentre as contribuições técnico científicas, duas estavam em branco e dentre as outras 05, nenhuma versou comentário ou anexou documento de teor técnico-científico para análise. Em relação ao perfil dos participantes das contribuições de experiência ou opinião, 10 contribuições foram enviadas por pessoa física, todas como profissional de saúde, e uma pessoa jurídica, identificada como Secretaria Municipal de Saúde. Nenhuma destas contribuições versou comentários sobre experiência com o teste, tampouco acerca de efeitos positivos e negativos relacionados ao seu uso. Nenhuma contribuição anexou documentos para análise neste relatório de recomendação. RECOMENDAÇÃO FINAL: Os membros do plenário presentes na 94ª reunião ordinária da Conitec, no dia 03 de fevereiro de 2021, deliberaram, por unanimidade, recomendar a incorporação, no SUS, do teste de fluxo lateral para detecção de lipoarabinomanano em urina (LF-LAM) para rastreamento e diagnóstico de tuberculose (TB) ativa em pessoas com suspeita de TB vivendo com HIV/AIDS (PVHIV). Não foram adicionadas na CP referências que alterassem a análise da evidência apresentada no relatório preliminar. Foi assinado o Registro de Deliberação nº 586/2021. DECISÃO: incorporar o teste de fluxo lateral para detecção de lipoarabinomanano em urina (LF-LAM) para rastreamento e diagnóstico de tuberculose ativa em pessoas suspeitas vivendo com HIV/AIDS, do Sistema Único de Saúde - SUS, conforme Portaria nº 02, publicada no Diário Oficial da União nº 34, seção 1, página 93, em 22 de fevereiro de 2021.


Assuntos
Humanos , Tuberculose/urina , Síndrome da Imunodeficiência Adquirida/fisiopatologia , Técnicas e Procedimentos Diagnósticos , Avaliação da Tecnologia Biomédica , Análise Custo-Eficiência , Sistema Único de Saúde
15.
PLoS Med ; 17(12): e1003466, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33306694

RESUMO

BACKGROUND: Lateral flow urine lipoarabinomannan (LAM) tests could offer important new opportunities for the early detection of tuberculosis (TB). The currently licensed LAM test, Alere Determine TB LAM Ag ('LF-LAM'), performs best in the sickest people living with HIV (PLHIV). However, the technology continues to improve, with newer LAM tests, such as Fujifilm SILVAMP TB LAM ('SILVAMP-LAM') showing improved sensitivity, including amongst HIV-negative patients. It is important to anticipate the epidemiological impact that current and future LAM tests may have on TB incidence and mortality. METHODS AND FINDINGS: Concentrating on South Africa, we examined the impact that widening LAM test eligibility would have on TB incidence and mortality. We developed a mathematical model of TB transmission to project the impact of LAM tests, distinguishing 'current' tests (with sensitivity consistent with LF-LAM), from hypothetical 'future' tests (having sensitivity consistent with SILVAMP-LAM). We modelled the impact of both tests, assuming full adoption of the 2019 WHO guidelines for the use of these tests amongst those receiving HIV care. We also simulated the hypothetical deployment of future LAM tests for all people presenting to care with TB symptoms, not restricted to PLHIV. Our model projects that 2,700,000 (95% credible interval [CrI] 2,000,000-3,600,000) and 420,000 (95% CrI 350,000-520,000) cumulative TB incident cases and deaths, respectively, would occur between 2020 and 2035 if the status quo is maintained. Relative to this comparator, current and future LAM tests would respectively avert 54 (95% CrI 33-86) and 90 (95% CrI 55-145) TB deaths amongst inpatients between 2020 and 2035, i.e., reductions of 5% (95% CrI 4%-6%) and 9% (95% CrI 7%-11%) in inpatient TB mortality. This impact in absolute deaths averted doubles if testing is expanded to include outpatients, yet remains <1% of country-level TB deaths. Similar patterns apply to incidence results. However, deploying a future LAM test for all people presenting to care with TB symptoms would avert 470,000 (95% CrI 220,000-870,000) incident TB cases (18% reduction, 95% CrI 9%-29%) and 120,000 (95% CrI 69,000-210,000) deaths (30% reduction, 95% CrI 18%-44%) between 2020 and 2035. Notably, this increase in impact arises largely from diagnosis of TB amongst those with HIV who are not yet in HIV care, and who would thus be ineligible for a LAM test under current guidelines. Qualitatively similar results apply under an alternative comparator assuming expanded use of GeneXpert MTB/RIF ('Xpert') for TB diagnosis. Sensitivity analysis demonstrates qualitatively similar results in a setting like Kenya, which also has a generalised HIV epidemic, but a lower burden of HIV/TB coinfection. Amongst limitations of this analysis, we do not address the cost or cost-effectiveness of future tests. Our model neglects drug resistance and focuses on the country-level epidemic, thus ignoring subnational variations in HIV and TB burden. CONCLUSIONS: These results suggest that LAM tests could have an important effect in averting TB deaths amongst PLHIV with advanced disease. However, achieving population-level impact on the TB epidemic, even in high-HIV-burden settings, will require future LAM tests to have sufficient performance to be deployed more broadly than in HIV care.


Assuntos
Lipopolissacarídeos/urina , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Biomarcadores/urina , Humanos , Incidência , Modelos Teóricos , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , África do Sul/epidemiologia , Fatores de Tempo , Tuberculose/mortalidade , Tuberculose/urina , Urinálise
16.
Sci Rep ; 10(1): 22317, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33339845

RESUMO

Despite efforts to improve tuberculosis (TB) detection, limitations in access, quality and timeliness of diagnostic services in low- and middle-income countries are challenging for current TB diagnostics. This study aimed to identify and characterise a metabolic profile of TB in urine by high-field nuclear magnetic resonance (NMR) spectrometry and assess whether the TB metabolic profile is also detected by a low-field benchtop NMR spectrometer. We included 189 patients with tuberculosis, 42 patients with pneumococcal pneumonia, 61 individuals infected with latent tuberculosis and 40 uninfected individuals. We acquired the urine spectra from high and low-field NMR. We characterised a TB metabolic fingerprint from the Principal Component Analysis. We developed a classification model from the Partial Least Squares-Discriminant Analysis and evaluated its performance. We identified a metabolic fingerprint of 31 chemical shift regions assigned to eight metabolites (aminoadipic acid, citrate, creatine, creatinine, glucose, mannitol, phenylalanine, and hippurate). The model developed using low-field NMR urine spectra correctly classified 87.32%, 85.21% and 100% of the TB patients compared to pneumococcal pneumonia patients, LTBI and uninfected individuals, respectively. The model validation correctly classified 84.10% of the TB patients. We have identified and characterised a metabolic profile of TB in urine from a high-field NMR spectrometer and have also detected it using a low-field benchtop NMR spectrometer. The models developed from the metabolic profile of TB identified by both NMR technologies were able to discriminate TB patients from the rest of the study groups and the results were not influenced by anti-TB treatment or TB location. This provides a new approach in the search for possible biomarkers for the diagnosis of TB.


Assuntos
Biomarcadores/urina , Diagnóstico Precoce , Metaboloma , Tuberculose/urina , Adulto , Idoso , Líquidos Corporais/metabolismo , Análise Discriminante , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Metabolômica/métodos , Pessoa de Meia-Idade , Tuberculose/microbiologia , Tuberculose/patologia
17.
PLoS One ; 15(10): e0241067, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33112923

RESUMO

Tuberculosis (TB) is a major global public health problem with high mortality and morbidity. In low-middle income countries (LMIC) a large number of respiratory symptomatic cases that require TB screening per year demands more accurate, fast and affordable testing for TB diagnostics. Sputum smear is the initial screening test in LMICs, however, its sensitivity is limited in patients with low sputum bacilli load. The same limitation is observed in the currently available molecular tests. We designed, standardized and evaluated an electrochemical biosensor that detects the highly specific DNA insertion element 6110 (IS6110). A PCR amplified DNA product is hybridized on the surface of the working electrode built on FTO-Glass with immobilized specific DNA probes, after which cyclic voltammetry is performed with an Ag/AgCl reference electrode and a platinum counter electrode. The response of the sensor was measured by the ratio (cathodic peak current of the hybridized sensor) / (cathodic peak current of the non-hybridized sensor). We tested the biosensor, using positive hybridization control sequences, genomic DNA extracted from M. tuberculosis strains and sputum of TB patients, and extracted DNA from the urine of healthy controls spiked with M. tuberculosis DNA. This biosensor was effective for the detection of M. tuberculosis DNA with a detection limit of 16 fM in sputum sample and 1 fM in spiked urine samples. The low cost and the relatively brief duration of the assay make this an important TB screening tool in the fight against tuberculosis.


Assuntos
Técnicas Biossensoriais/métodos , Eletroquímica/métodos , Mycobacterium tuberculosis/genética , Escarro/microbiologia , Tuberculose/diagnóstico , Urinálise/métodos , DNA Bacteriano , Humanos , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/genética , Tuberculose/microbiologia , Tuberculose/urina
18.
BMC Infect Dis ; 20(1): 555, 2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32736601

RESUMO

BACKGROUND: Determine TB-LAM is the first point-of-care test (POC) for HIV-associated tuberculosis (TB) and rapidly identifies TB in those at high-risk for short-term mortality. While the relationship between urine-LAM and mortality has been previously described, the outcomes of those undergoing urine-LAM testing have largely been assessed during short follow-up periods within diagnostic accuracy studies. We therefore sought to assess the relationship between baseline urine-LAM results and subsequent hospitalization and mortality under real-world conditions among outpatients in the first year of ART. METHODS: Consecutive, HIV-positive adults with a CD4 count < 100 cells/uL presenting for ART initiation were enrolled. TB diagnoses and outcomes (hospitalization, loss-to-follow and mortality) were recorded during the first year following enrolment. Baseline urine samples were retrospectively tested using the urine-LAM POC assay. Kaplan Meier survival curves were used to assess the cumulative probability of hospitalization or mortality in the first year of follow-up, according to urine-LAM status. Cox regression analyses were performed to determine independent predictors of hospitalization and mortality at three months and one year of follow-up. RESULTS: 468 patients with a median CD4 count of 59 cells/uL were enrolled. There were 140 patients (29.9%) with newly diagnosed TB in the first year of follow-up of which 79 (56.4%) were microbiologically-confirmed. A total of 18% (n = 84) required hospital admission and 12.2% (n = 57) died within a year of study entry. 38 out of 468 (8.1%) patients retrospectively tested urine-LAM positive - including 19.0% of those with microbiologically-proven TB diagnoses (n = 15/79) and 23.0% (n = 14/61) of those with clinical-only TB diagnoses; 9 of 38 (23.7%) of patients retrospectively testing LAM positive were never diagnosed with TB under routine program conditions. Among all patients (n = 468) in the first year of follow-up, a positive urine-LAM result was strongly associated with all-cause hospitalization and mortality with a corresponding adjusted hazard ratio (aHR) of 3.7 (95%CI, 1.9-7.1) and 2.6 (95%, 1.2-5.7), respectively. CONCLUSIONS: Systematic urine-LAM testing among ART-naïve HIV-positive outpatients with CD4 counts < 100 cells/uL detected TB cases that were missed under routine programme conditions and was highly predictive for subsequent hospitalization and mortality in the first year of ART.


Assuntos
Infecções por HIV/complicações , Lipopolissacarídeos/urina , Tuberculose/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/urina , Contagem de Linfócito CD4 , Feminino , Seguimentos , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Pacientes Ambulatoriais/estatística & dados numéricos , Testes Imediatos , Estudos Prospectivos , Estudos Retrospectivos , África do Sul/epidemiologia , Resultado do Tratamento , Tuberculose/mortalidade , Tuberculose/terapia , Tuberculose/urina , Urinálise/métodos
19.
PLoS One ; 15(1): e0227138, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31999746

RESUMO

BACKGROUND: Tuberculosis (TB) is the leading cause of death among HIV-positive patients. We assessed the cost-effectiveness of including lateral-flow urine lipoarabinomannan (LF-LAM) in TB diagnostic algorithms for severely ill or immunosuppressed HIV-positive patients with symptoms of TB in Kenya. METHODS: From a decision-analysis tree, ten diagnostic algorithms were elaborated and compared. All algorithms included clinical exam. The costs of each algorithm were calculated using a 'micro-costing' method. The efficacy was estimated through a prospective study that included severely ill or immunosuppressed (CD4<200cells/µL) HIV-positive adults with symptoms of TB. The cost-effectiveness analysis was performed using the disability-adjusted life year (DALY) averted as effectiveness outcome. A 4% discount rate was applied. RESULTS: The algorithm that added LF-LAM alone to the clinical exam lead to the least average cost per TB case detected (€47) and was the most cost-effective with a cost/DALY averted of €4.6. The algorithms including LF-LAM, microscopy and X-ray, and LF-LAM and Xpert in sputum, detected a high number of TB cases with a cost/DALY averted of €6.1 for each of them. In the comparisons of the algorithms two by two, using LF-LAM instead of microscopy (clinic&LAM vs clinicµscopy) and using LF-LAM along with GeneXpert in sputum instead of GeneXpert in urine along with GeneXpert in sputum, (clinic&LAM&Xpert_sputum vs clinic&Xpert_sputum&Xpert_urine) led to the highest increase in the cost-effectiveness ratios (ICERs): €-7.2 and €-12.6 respectively. In these two comparisons, using LF-LAM increased the number of TB patients detected while reducing costs. Adding LF-LAM to smear microscopy alone or to smear microscopy and Xray led to the highest increase in the additional number of TB cases detected (31 and 25 respectively) with an incremental efficiency estimated at 134 and 344 DALYs respectively. The ICERs were €22.0 and €8.6 respectively. CONCLUSION: Including LF-LAM in TB diagnostic algorithms is cost-effective for severely ill or immunosuppressed HIV-positive patients.


Assuntos
Análise Custo-Benefício , Infecções por HIV/complicações , Lipopolissacarídeos/urina , Técnicas de Diagnóstico Molecular/economia , Tuberculose/diagnóstico , Adulto , Biomarcadores/urina , Feminino , Humanos , Masculino , Tuberculose/urina
20.
Am J Trop Med Hyg ; 102(3): 562-566, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31971152

RESUMO

Point-of-care urine-lipoarabinomannan (LAM) Alere Determine TB-LAM assay has shown utility diagnosing tuberculosis (TB) in HIV-positive, severely immunocompromised, TB-symptomatic patients. We assessed LAM results in severely immunocompromised patients, who had LAM systematically performed at new or follow-up HIV consultations. This was a prospective, observational study on consecutive ambulatory, > 15-year-old HIV-positive patients with CD4 < 100 cells/µL in Mozambique. Clinical assessments and LAM were performed for all and microscopy, Xpert, sputum culture, and chest X-ray for LAM-positive participants. Patients were followed up for 6 months. Of 360 patients, half were ART-naive. Lipoarabinomannan positivity was 11.9% (43/360), higher among symptomatic patients compared with asymptomatic: 18.5% (30/162), and 6.6% (13/198), respectively, P = 0.001. Tuberculosis was bacteriologically confirmed in 6/35 LAM-positive patients (2 of them asymptomatic). Lipoarabinomannan positivity was associated with higher risk of mortality (adjusted odds ratio [aOR]: 4.6, 95% CI: 1.3-15.6, P = 0.015). Systematic urine-LAM allows for rapid TB treatment initiation in severely immunocompromised HIV ambulatory patients and identifies patients at a higher risk of death.


Assuntos
Infecções por HIV/complicações , Infecções por HIV/patologia , Lipopolissacarídeos/urina , Testes Imediatos , Tuberculose/diagnóstico , Urinálise/métodos , Adulto , Feminino , Infecções por HIV/urina , HIV-1 , Humanos , Hospedeiro Imunocomprometido , Masculino , Tuberculose/complicações , Tuberculose/urina
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