Identification and Assessment of Surrogate Biomarkers for Chronic Chagas Disease

虽然低级寄生虫的持久性是慢性恰加斯病的一个基本方面，但目前的寄生虫学检测灵敏度低，而且不是定量的。苯硝唑是唯一可用的杀锥虫药物，在治疗慢性恰加斯病患者方面的疗效值得怀疑。目前迫切需要进行治疗慢性恰加斯病的新药的临床试验，然而，缺乏可靠的生物标记物来减少寄生虫和由此引起的炎症反应和损害是评价新药的主要障碍。7.寄生虫的存在和水平以及由此引起的免疫和炎症扰动的区分标记的鉴定可能潜在地解决这个问题。寄生虫和疾病进展的少数可用生物标志物既不是定量的，也不是高度可预测的。众所周知，与单一标志物相比，复合生物标志物在区分临床结果方面具有更高的潜力。血液基因表达谱已被用于区分几种感染性疾病中不同感染过程的患者，包括我们查加斯病小组的初步数据。我们假设，7.克鲁兹病毒的持续寄生会导致PBMC基因表达模式的特殊变化。第二个假设是，根据临床表现和发现以及7.CRUZI聚合酶链式反应和抗体结果确定的不同感染阶段，将显示特定的复合生物标志物特征。这个项目的主要目的是识别高度和低7.克鲁兹寄生症的转录图谱以及具有不同临床表现的患者的转录图谱，并将转录组分析的结果与我们目前正在表征的其他生物标记物参数相结合。这项研究将评估来自Reds II Chagas队列的代表恰加斯病不同临床阶段和寄生虫强度的患者样本(由7.CRUZI实时聚合酶链式反应测量)以及血清阴性对照。将对全血进行转录组分析，与每个临床组相关的转录签名将通过可应用于更大样本集的qPCR分析进行验证。然后，我们将测试验证的信使核糖核酸标记物对其余的瑞德II恰加斯病队列(600名患者和100名血清阴性对照)的分类能力。炎症和心血管疾病的血浆蛋白生物标记物和7.Cruz/抗体图谱/滴度将与转录组签名相结合，构建用于预后和治疗监测的改进的复合生物标记物图谱。

Although low-grade parasite persistence is a fundamental aspect of chronic Chagas disease, current parasitological assays have low sensitivity and are not quantitative. Benznidazole, the only available trypanocidal drug, has questionable efficacy in the treatment of chronic Chagas disease patients. There is an urgent need to perform clinical trials of new drugs for chronic Chagas disease, however the lack of reliable biomarkers for reduction of parasitism and consequent inflammatory responses and damage is a major obstacle for evaluating new drugs. The identification of differentiating markers for presence and levels of 7. crtvz; parasitism and resulting immune and inflammatory perturbations could potentially solve this problem. The few available biomarkers for parasitism and disease progression are neither quantitative nor highly predictive. It is known that composite biomarkers have a higher potential for differentiating clinical outcomes than single markers. Blood gene expression profiling has been used to differentiate between patients with distinct courses of infection in several infectious diseases including preliminary data from our group for Chagas disease. We hypothesize that persistent parasitism by 7. cruzi, induces specific changes in PBMC gene expression patterns. A second hypothesis is that distinct stages of infection, defined based on clinical presentation and findings and 7. cruzi PCR and antibody results, will display specific composite biomarker profiles. The major aims of this project are to identify the transcriptional profiles of high and low 7. cruzi parasitism as well as the transcriptional profiles of patients with different clinical presentations, and to combine the findings from transcriptome analyses with other biomarker parameters we are currently characterizing. The study will evaluate a sample of patients representative of distinct clinical stages of Chagas disease and intensity of parasitism (as measured by 7. cruzi real-time PCR), along with seronegative controls, from the REDS II Chagas cohort. Transcriptome analysis of whole blood will be performed, and transcriptional signatures that correlate with each clinical group will be validated with qPCR assays that can be applied to larger sample sets. We will then test the classifying ability of validated mRNA markers on the remainder of the REDS II Chagas disease cohort (600 patients and 100 seronegative controls). Plasma protein biomarkers of inflammation and cardiovascular disease and 7. cruz/antibody profiles/titers, which are being characterized in the same patient groups, will be combined with transcriptome signatures to construct an improved composite biomarker profile for prognosis and therapeutic monitoring.