Serological test for detecting all geographical variances of Trypanosoma cruzi infection

恰加斯病是一种被忽视的热带疾病，是拉丁美洲的地方病，但越来越多地被 在美国发现的。查加斯病是由克氏锥虫（Trypanosoma cruzi）（T. cruzi）寄生虫和 它分为两个阶段：急性期和慢性期。这两个阶段的诊断是具有挑战性的 因为患者可能无症状或具有非特异性症状。如果不治疗，急性感染会发展为 慢性期，其中20 - 40%的患者将发展危及生命的疾病，包括心肌病，心脏病， 衰竭和心脏骤停 急性感染可通过显微镜检查发现;然而，慢性感染期间的寄生虫血症水平 低于该技术的检测极限，使其不适合诊断。因此，诊断 慢性感染的诊断主要依靠血清学检测抗-T。克氏抗体，它可以持续在 血液在感染者的一生中。然而，现有的血清学检测容易产生不确定性， 或由于天然T细胞不足而导致的假阴性/阳性结果。这些测定中使用的Cruzi捕获蛋白 以及7个T. cruzi离散分型单位（DTU）亚型。因此，世卫组织和 泛美卫生组织建议使用至少两种不同的血清学技术进行检测，以诊断恰加斯病感染。 在美国，如果这两种检测结果不一致，则需要将样本转交给 CDC进行额外检测以确认诊断。这种重复的测试过程占用了大量的资源 卫生保健系统的负担和现有查加斯血清学检测的不良表现可能导致 增加疾病传播和因误诊而危及生命的疾病。因此，这一目标 本项目旨在开发一种能准确检测所有地理变异的T.克氏感染 该试验将采用精心设计的重组T细胞集。高特异性cruzi抗原 检测所有T. Cruzi亚型，而与其他病原体没有交叉反应性。的理由 所提出的研究得到了申请人的初步数据的支持， 重组T. Cruzi抗原（Tc 24）能准确检测抗T.来自多个人源的人血清中的cruzi IgG 查加斯流行国家和高灵敏度的抗T。使用磁电机测定人血清中的cruzi IgG 免疫分析原型。为了实现这一目标，我们将努力实现以下具体目标： 1)鉴定用于检测所有T. cruzi亚型特异性高; 2)建立一种高灵敏度、高特异性的T.克鲁兹 这种方法是创新的，因为它结合了使用一系列精心设计的重组T。 cruzi抗原用于检测T. Cruzi，同时与其他药物没有交叉反应性， 寄生虫与敏感的磁免疫测定，这是有意义的，因为它将提高诊断 这将有助于减少慢性南美锥虫病患者的发病率和死亡率。

Chagas disease is a neglected tropical disease that is endemic to Latin America, but is increasingly being detected in the United States. Chagas disease is caused by the Trypanosoma cruzi (T. cruzi) parasite and presents itself in two phases: an acute phase and chronic phase. The diagnosis of both phases is challenging as patients can be asymptomatic or have nonspecific symptoms. If untreated, acute infection progresses to a chronic phase where 20 ‒ 40% of patients will develop life-threatening illness, including cardiomyopathy, heart failure and cardiac arrest. Acute infection can be detected by microscopy; however, the level of parasitemia during chronic infection drops below the limit of detection of this technique, making it unsuitable for diagnosis. Therefore, the diagnosis of chronic infection relies mainly on serological detection of anti-T. cruzi antibodies, which can persist in the blood throughout the life of the infected individual. However, existing serological tests are prone to inconclusive or false-negative/positive results due to inadequacies of the native T. cruzi capture proteins used in these assays and differences in the seven T. cruzi discrete typing units (DTUs) subtypes. For these reasons, the WHO and PAHO recommends testing using at least two different serological techniques for diagnosing Chagas infection. In the United States, discordant results obtained from these two tests require the sample to be forwarded to the CDC for additional testing to confirm diagnosis. This repetitive testing process imposes a significant resource burden on the healthcare system and the poor performance of existing Chagas serological tests can lead to increased disease transmission and life-threatening illness due to misdiagnosis. Therefore, the objective of this project is to develop a serological test that can accurately detect all geographical variances of T. cruzi infection. This assay will employ a collection of carefully designed recombinant T. cruzi antigens for highly specific detection of all T. cruzi subtypes while exhibiting no cross-reactivity with other pathogens. The rationale for the proposed research is supported by the applicants’ preliminary data demonstrating the generation of a recombinant T. cruzi antigen (Tc24) that can accurately detect anti-T. cruzi IgG in human sera from multiple Chagas-endemic countries and highly sensitive detection of anti-T. cruzi IgG in human sera using a magneto immunoassay prototype. To achieve this goal, we will pursue the following specific aims: 1) Identify a collection of recombinant antigens for detecting all T. cruzi subtypes with high specificity; 2) Develop a magneto immunoassay for high sensitivity and specificity detection of T. cruzi. This approach is innovative because it combines the use of a collection of carefully designed recombinant T. cruzi antigens for detecting all geographic subtypes of T. cruzi while exhibiting no cross-reactivity with other parasites with a sensitive magneto immunoassay, and it is significant because it will improve the diagnosis of patients with chronic Chagas disease, thus helping to reduce disease-related morbidity and mortality.