Prospective Longitudinal Assessment of Culture-Independent Molecular Airway Markers of Nontuberculous Mycobacteria

大量证据表明，非结核分枝杆菌(NTM)是人类疾病的重要病原体。 囊性纤维化(CF)和其他阻塞性肺疾病。目前，呼吸道培养是由 所有的诊断和治疗决策都以此为基础。慢性非霍奇金淋巴瘤缺乏敏感、特异的标志物 呼吸道阻碍了患者护理和临床试验设计。NTM感染的非培养标志有 克服标准NTM培养的许多限制的潜力，特别是非常缓慢的生长(向上 至8周)，无法量化细菌负荷，以及由于需要去污而敏感度低 程序。挥发性代谢物分析和多重基因测序的初步数据 同时对相同的痰样本进行了快速、定量的检测 对NTM的敏感性超过标准培养。2018年，由CF基金会赞助的预测 《囊性纤维化中NTM疾病的前瞻性评估》和《耐心(前瞻性)》 治疗囊性纤维化中NTM的算法，NCT02419989)试验将扩大到10个CF方案 在全国范围内标准化诊断和测试基于方案的非传染性支气管炎肺治疗方法 疾病。这些试验为发展非结核分子标记提供了理想的平台 疾病状况。作为对PAR-18-643 NHLBI临床辅助研究的回应，这项提案将测试中央 假设：与痰培养相比，培养无关的标记集在检测是否存在方面具有优势 细菌总数、预测临床意义和评估CF型呼吸道NTM的治疗反应。作为一名 预测和耐心试验的时间敏感型辅助研究，目标1将测试痰的效用 挥发性代谢物作为呼吸道NTM的非培养标记物。目标2将测试痰的效用 多重基因测序作为呼吸道NTM的分子标志物，Aim 3将测试 挥发性代谢物和多重基因测序数据结合标准培养结果进行鉴定 更容易患上NTM病和/或对治疗有反应的受试者。 如果成功，对儿童和成人患者样本的横断面和纵向分析 明确的NTM感染状况将揭示每种检测方法单独和组合的优势和劣势， 与标准培养法检测和鉴定非霍奇金杆菌的比较 感染。这些标记可用于定期筛查NTM的高危人群，以便于 及早发现。此外，这些检测方法有可能区分惰性感染和 NTM疾病，以及对治疗反应的纵向监测和确定是否根除 病原体已达到或已达到亚临床阈值，这可能标志着 治疗。长期目标是向CF患者提供经过验证的NTM呼吸道疾病标志物 适用于所有有呼吸道疾病风险的非传染性支气管炎患者。

A preponderance of evidence has identified nontuberculous mycobacteria (NTM) as important pathogens in cystic fibrosis (CF) and other obstructive lung diseases. Currently, airway cultures are the “gold standard” by which all diagnosis and treatment decisions are based. The lack of sensitive and specific markers of NTM in the airway impedes patient care and clinical trial design. Culture-independent markers of NTM infection have the potential to overcome many of the limitations of standard NTM cultures, especially the very slow growth (up to 8 weeks), inability to quantitate bacterial burden, and low sensitivity due to required decontamination procedures. Preliminary data from analysis of volatile metabolites and multiplex gene sequencing performed simultaneously on the same sputum samples have demonstrated rapid, quantifiable detection of the presence of NTM that exceeds the sensitivity of standard cultures. In 2018, the CF Foundation-sponsored PREDICT (PRospective Evaluation of NTM Disease In CysTic Fibrosis, NCT02073409) and PATIENCE (Prospective Algorithm for Treatment of NTM in Cystic Fibrosis, NCT02419989) trials will be expanded to 10 CF Programs nationwide to standardize the diagnosis and test a protocol-based approach to treatment of NTM pulmonary disease. These trials represent an ideal platform to advance development of molecular markers of NTM disease status. In response to PAR-18-643 NHLBI Clinical Ancillary Studies, this proposal will test the Central Hypothesis: Culture-independent marker sets have advantages over sputum cultures for detecting presence of bacteria, predicting clinical significance and assessing treatment response of NTM in the CF airway. As a time-sensitive ancillary study to the PREDICT and PATIENCE trials, Aim 1 will test the utility of sputum volatile metabolites as culture-independent markers of airway NTM. Aim 2 will test the utility of sputum multiplex gene sequencing as molecular markers of airway NTM, and Aim 3 will test the combination of volatile metabolites and multiplex gene sequencing data combined with standard culture results to identify subjects more likely to develop NTM disease and/or respond to treatment. If successful, the cross-sectional and longitudinal analyses of samples from pediatric and adult patients with well-defined NTM infection status will reveal the strengths and weakness of each assay alone and combined, in comparison to standard culture for the detection and identification of NTM in the presence of bacterial co- infection. These markers can be applied to periodic screening of patient populations at risk for NTM to facilitate early detection. In addition, these assays have the potential to differentiate between indolent infection and NTM disease, as well as longitudinal monitoring of response to treatment and determination if eradication of the pathogen has been achieved or a subclinical threshold has been reached, which could signal end of treatment. The long-term goal is to deliver validated markers of NTM airway disease to the CF patient population, with applicability to all patient populations with respiratory conditions at risk for NTM disease.