Quantifiable stool-based TB PCR to Improve Diagnostics and Treatment Monitoring

基于粪便的可量化结核病 PCR 改善诊断和治疗监测

基本信息

批准号：
10437815
负责人：
ANNA M MANDALAKAS
金额：
$ 81.48万
依托单位：
BAYLOR COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-01 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10437815
关键词：
Adolescent Adult Antigens Antitubercular Agents Bacteriology Biological Assay Caring Cause of Death Cessation of life Characteristics Child Clinical Collection Colony-forming units DNA DNA-Directed RNA Polymerase Data Detection Diagnostic Diagnostic tests Drug resistance Drug resistance in tuberculosis Effectiveness Evaluation Feces Generations Genes Genotype HIV HIV Infections Health Health Personnel Hour Individual Laboratories Lateral Liquid substance Measures Microscopy Molecular Monitor Mozambique Multicenter Studies Mutation Mycobacterium tuberculosis Outcome Parents Participant Patient Care Patient-Focused Outcomes Patients Perception Persons Pharmaceutical Preparations Phenotype Population Positioning Attribute Predisposition Proxy Quantitative Evaluations Radiology Specialty Rapid diagnostics Reference Standards Relapse Research Research Project Grants Resistance Resolution Rifampicin resistance Risk Site Specimen Sputum Swaziland Symptoms Tanzania Techniques Testing Time Treatment Failure Treatment Protocols Treatment outcome Tuberculosis Tuberculosis diagnosis Urine Vulnerable Populations Work accurate diagnosis base clinical diagnosis design detection limit diagnostic accuracy drug development feasibility testing genome sequencing improved innovation lipoarabinomannan performance tests respiratory sample collection tool treatment response tuberculosis diagnostics tuberculosis treatment whole genome

项目摘要

PROJECT SUMMARY Mycobacterium tuberculosis (Mtb), the world’s leading infectious killer, results in 1.8 million deaths and 10.4 million new cases annually. Despite recent advancements, >40% of cases are missed with diagnostic gaps greatest in children and people living with HIV (PLWH) in whom treatment delay contributes to poor outcomes. Current TB diagnostic tests lack sensitivity in children and PLWH. Culture is often inaccessible in TB high- burden settings, has a long delay to result, and poorly predicts treatment failure and relapse. Xpert Ultra (Ultra) yields results in ~2 hours, but Ultra sensitivity is 63% in smear-negative, culture-positive adults and 67% in child TB, and relies upon difficult to collect respiratory specimens. Recognizing these limitations, we developed a stool based quantifiable PCR (qPCR) whose initial evaluations show i) a limit of detection equivalent to culture at 96 colony forming units per 50mg of stool, ii) sensitivity equivalent to sputum-based Xpert, and iii) 20- 30% increased yield amongst Xpert and culture-negative individuals with clinical TB. We are now poised to validate our findings in adults, adolescents, and children with and without HIV-infection in a multi-centered study at our sites in Swaziland, Tanzania and Mozambique. TB treatment response is monitored by symptom resolution, radiologic improvement, serial microscopy and culture. As 45% of HIV-associated and 80% of child TB is smear-negative, treatment monitoring in these key populations is limited to poorly sensitive symptomatic evaluation. Our pilot work demonstrates that persistent detection of Mtb by qPCR after 2 months of TB treatment was associated with 3-fold increased odds of treatment failure. We are now positioned to assess the treatment monitoring potential of qPCR and discriminate between participants who will fail treatment and participants who will achieve relapse free cure. TB treatment outcomes are optimized by minimizing time to appropriate treatment. Available drug susceptibility tests (Xpert and Line Probe Assay) are limited by reliance on smear-positive respiratory specimens and test placement at central laboratories. Stool-based genotypic drug susceptibility testing (DST) could provide clinicians with data to guide appropriate TB treatment, particularly in sputum smear negative patients, and avert the development of drug resistance. Building on our stool-based platform, we will assess the feasibility and test performance of LPA completed on DNA isolated from stool. Current sputum collection techniques are poorly accepted by patients, parents and health care workers. The impact of any diagnostic test is influenced by feasibility of implementation and acceptability. To comprehensively assess the potential impact of our stool-based platform, we will gather critical data regarding operational characteristics, acceptability and perceptions. Rapid, affordable tests that i) accurately diagnose TB, ii) robustly identify drug-resistance, and iii) guide treatment from accessible non-respiratory specimens could revolutionize TB care and control.

项目摘要分枝杆菌结核病（MTB）是世界领先的传染性杀手，导致180万人死亡和10.4 每年数百万个新案件。尽管最近的进步，> 40％的病例被诊断差距遗漏在儿童和艾滋病毒（PLWH）的儿童中，治疗延迟会导致不良结果。当前的结核病诊断测试缺乏儿童和PLWH的敏感性。在结核病高 - 负担设置，结果很长，并且很难预测治疗失败和缓解。 Xpert Ultra（Ultra）收益率为2小时，但涂片阴性的培养阳性成年人的超灵敏度为63％，在67％中为67％儿童结核病，并依靠难以收集呼吸标本。认识到这些局限性，我们开发了基于凳子的可量化PCR（QPCR），其初始评估显示i）检测限量等效于每50毫克粪便，在96个菌落形成单位的培养，ii）相当于基于痰液的Xpert的灵敏度，iii）20- XPERT和培养阴性个体的临床结核病患者的产量增加了30％。我们现在被中毒验证我们在成人，青少年和患有和没有HIV感染的儿童中的发现在我们位于斯威士兰，坦桑尼亚和莫桑比克的网站上学习。结核病治疗反应通过症状分辨率，放射学改善，连续显微镜和文化。由于45％的HIV相关和80％的儿童结核病为涂片，因此在这些密钥中进行治疗监测种群仅限于症状评估敏感的敏感性不佳。我们的飞行员工作表明了持久在2个月的结核病治疗后通过qPCR检测MTB与3倍增加的几率增加治疗失败。现在，我们可以评估QPCR的治疗监测潜力和区分将失败治疗的参与者和将实现无继电器治疗的参与者。通过最大程度地减少适当治疗的时间，可以优化结核病治疗结果。可用药物易感性测试（XPERT和线探针测定）受到涂片阳性呼吸的缓解的限制中央实验室的标本和测试放置。基于粪便的基因型药物敏感性测试（DST）可以为临床医生提供指导适当的结核病治疗的数据，尤其是在痰涂片阴性中患者，并避免耐药性的发展。在基于凳子的平台上，我们将评估 LPA的可行性和测试性能从粪便分离的DNA上完成。当前的痰收集技术被患者，父母和卫生保健工作者所接受。任何诊断测试的影响都受到实施和可接受性的可行性的影响。到全面评估基于凳子的平台的潜在影响，我们将收集有关有关的关键数据操作特征，可接受性和看法。快速，负担得起的测试，i）准确诊断结核病，ii）鲁棒性识别抗药性和iii）指南可访问的非呼吸标本的治疗可能会彻底改变结核病护理和控制。