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

• 批准号: 10208666
• 负责人: ANNA M MANDALAKAS
• 金额: $ 60.4万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10208666
• 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; Diagnosis; 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; 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; 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

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.

项目概要 结核分枝杆菌 (Mtb) 是世界上主要的传染病杀手，导致 180 万人死亡，10.4 人死亡。 尽管最近取得了进展，但仍有超过 40% 的病例因诊断缺陷而被漏诊。 儿童和艾滋病毒感染者（PLWH）的情况最为严重，他们的治疗延迟会导致不良结果。 目前的结核病诊断测试对儿童缺乏敏感性，而结核病高发人群往往无法进行培养。 负担设置，结果延迟很长，并且很难预测治疗失败和复发。 约 2 小时即可得出结果，但涂片阴性、培养阳性成人的超敏感性为 63%，而在 认识到这些局限性，我们开发了儿童结核病疫苗。 基于粪便的可定量 PCR (qPCR)，其初步评估显示 i) 检测限相当于 每 50 毫克粪便培养 96 个菌落形成单位，ii) 灵敏度相当于基于痰的 Xpert，以及 iii) 20- Xpert 和培养阴性临床结核病患者的产量增加了 30%，我们现在已做好准备。 在多中心研究中验证我们对感染或未感染 HIV 的成人、青少年和儿童的研究结果 在我们位于斯威士兰、坦桑尼亚和莫桑比克的工厂进行研究。 结核病治疗反应通过症状消退、放射学改善、连续显微镜检查和 由于 45% 的艾滋病毒相关者和 80% 的儿童结核病涂片呈阴性，因此需要对这些关键点进行治疗监测。 我们的试点工作表明，这种情况持续存在。 结核病治疗 2 个月后，通过 qPCR 检测 Mtb 的几率增加 3 倍 我们现在准备评估 qPCR 和治疗监测的潜力。 区分治疗失败的参与者和实现无复发治愈的参与者。 结核病治疗结果随着时间的推移而优化，以尽量减少可用的药物。 药敏试验（Xpert 和 Line Probe Assay）因依赖涂片阳性呼吸道检测而受到限制 中央实验室的样本和测试安排。基于粪便的基因型药物敏感性测试（DST）。 可以提供上级数据来指导适当的结核病治疗，特别是痰涂片阴性的情况 患者，并避免耐药性的发展 基于我们的粪便平台，我们将进行评估。 对从粪便中分离的 DNA 完成 LPA 的可行性和测试性能。 目前的痰液收集技术尚未被患者、家长和医护人员接受。 任何诊断测试的影响都受到实施的可行性和可接受性的影响。 全面评估我们基于粪便的平台的潜在影响，我们将收集以下方面的关键数据 操作特征、可接受性和看法。 快速、经济实惠的检测，i) 准确诊断结核病，ii) 可靠地识别耐药性，以及 iii) 指导 利用可获取的非呼吸道样本进行治疗可能会彻底改变结核病的护理和控制。