M. tuberculosis exosome detection for pediatric TB diagnosis

结核分枝杆菌外泌体检测用于儿童结核病诊断

基本信息

批准号：
10325946
负责人：
Sylvia LaCourse
金额：
$ 69.64万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-21 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10325946
关键词：
5 year old Adult Antigens Aspirate substance Bacille Calmette-Guerin vaccination Bayesian Method Biological Assay Biological Markers Blood Blood specimen Car Phone Cell Compartmentation Cessation of life Child Childhood Clinical Clinical Data Clinical Treatment Collection Cryopreservation Detection Development Diagnosis Diagnostic Disease Enrollment Epidemiologic Methods Equation Evaluation Future Gaussian model Gold HIV Highly Active Antiretroviral Therapy Household Immune response Immunological Models Infant Investigation Kenya Link Lipoproteins Malignant Neoplasms Measures Methods Microbiology Microscopy Modeling Molecular Genetics Monitor Morbidity - disease rate Mycobacterium tuberculosis Participant Pathogenesis Patients Pediatric cohort Performance Play Prevalence Prospective cohort Proteins Rapid diagnostics Reference Standards Research Personnel Risk Role Sampling Sensitivity and Specificity Serum Specimen Sputum Stomach Surrogate Markers Surveys Technology Testing Time Treatment Failure Tuberculosis Tuberculosis Vaccines Uncertainty Urine base biological specimen archives biomarker discovery cohort cost exosome experience extracellular vesicles field study improved lipoarabinomannan macrophage molecular diagnostics mortality mycobacterial nanotechnique novel diagnostics pediatric human immunodeficiency virus peripheral blood point of care prognostic prospective prototype respiratory response tool treatment response tuberculosis treatment vaccine trial

项目摘要

PROJECT SUMMARY/ABSTRACT Over one million new cases of tuberculosis (TB) and 239,000 TB-related deaths occur in children each year. Young children, especially those with HIV, are more likely to present with disseminated or extrapulmonary TB and paucibacillary disease, often missed by respiratory sampling. Non-sputum, biomarker-based diagnostic tools for rapid TB detection and treatment response in children, using easily obtained specimens are urgently needed. Exosomes are small (30-100 nm) membranous extracellular vesicles (EVs) originating from endosomal cell compartments; those secreted by M. tuberculosis (Mtb) or Mtb-infected macrophages appear to play a significant role in Mtb pathogenesis. Our collaborators have developed a rapid and sensitive nanoplasmon-enhanced scattering (nPES) assay which directly detects Mtb-exosomes (Mtb-EVs) from as little as 1 L of serum. Proof- of-concept nPES assays performed with Mtb markers LpqH (19-kDa Mtb lipoprotein) and LAM distinguished adult TB from at-risk patients and normal controls, and among pediatric TB cases (including HIV+) and controls with high sensitivity and specificity. We propose using archived specimens and clinical data from the Pediatric Urgent Start of HAART (PUSH) Study (NCT02063880) and a new proposed prospective cohort of children suspected of TB with high HIV prevalence to evaluate performance of nPES detected Mtb-EVs for pediatric TB diagnosis (Aim 1), treatment response (Aim 2), and evaluation of a point-of-care platform (Aim 3). In addition to assessing conventional diagnostic performance measures, we propose to use advanced epidemiologic methods (Bayesian latent class analysis) given the context of an imperfect reference. Additional evaluation in adult TB patients and healthy controls including household contacts (adults and children) and recently BCG-vaccinated infants without TB is proposed. We hypothesize nPES detected Mtb-EVs will 1) have similar diagnostic performance to the reference of Xpert/culture among children with confirmed TB without the need for sputum, and identify additional children missed by respiratory sample, 2) will provide a useful surrogate marker of treatment response with decline in quantitative levels during successful treatment, and 3) will maintain performance with a point-of-care platform. Using cryopreserved samples from a well-characterized cohort of children with HIV who underwent intensive TB evaluation and a prospective cohort of children suspected of TB with high HIV prevalence provides opportunity for efficient evaluation of a novel diagnostic with potential for clinical impact to improve pediatric TB diagnosis.

项目概要/摘要每年有超过 100 万儿童结核病 (TB) 新病例和 239,000 例与结核病相关的死亡。幼儿，尤其是感染艾滋病毒的儿童，更有可能出现播散性或肺外结核病和少杆菌疾病，通常会被非痰、基于生物标志物的诊断工具漏掉。为了快速检测儿童结核病并做出治疗反应，迫切需要使用容易获得的标本。外泌体是源自内体细胞的小型（30-100 nm）膜状细胞外囊泡（EV）结核分枝杆菌 (Mtb) 或感染 Mtb 的巨噬细胞分泌的细胞似乎发挥着重要作用。我们的合作者开发了一种快速、灵敏的纳米等离子体增强剂。散射 (nPES) 测定可直接从低至 1 μL 的血清中检测 Mtb-外泌体 (Mtb-EV)。使用 Mtb 标记物 LpqH（19-kDa Mtb 脂蛋白）和 LAM 进行概念性 nPES 检测来自高危患者和正常对照的成人结核病，以及儿科结核病病例（包括 HIV+）和对照人群的结核病具有高灵敏度和特异性。我们建议使用来自儿科紧急启动 HAART (PUSH) 研究的存档标本和临床数据 (NCT02063880) 和一个新提出的前瞻性队列，其中包括疑似结核病且艾滋病毒感染率高的儿童评估 nPES 检测到的 Mtb-EV 在儿童结核病诊断（目标 1）、治疗反应（目标 2)，除了评估传统诊断之外，还评估即时护理平台（目标 3）。绩效衡量，我们建议使用先进的流行病学方法（贝叶斯潜在类别分析）鉴于对成年结核病患者和健康对照的补充评估不完善。建议包括家庭接触者（成人和儿童）和最近接种过卡介苗的未患结核病的婴儿。我们勇敢地 nPES 检测到 Mtb-EV 将 1) 具有与参考相似的诊断性能无需痰液即可对确诊结核病的儿童进行 Xpert/培养，并确定其他儿童呼吸道样本遗漏，2）将提供治疗反应的有用替代标志物成功治疗期间的定量水平，3) 将通过护理点平台保持性能。使用来自接受强化结核病治疗的特征明确的艾滋病毒儿童队列的冷冻保存样本评估和对疑似结核病且艾滋病毒感染率高的儿童进行前瞻性队列研究提供了机会有效评估具有临床影响的新诊断，以改善儿科结核病诊断。