Serological test for detecting all geographical variances of Trypanosoma cruzi infection

用于检测克氏锥虫感染所有地理差异的血清学检测

• 批准号: 10666966
• 负责人: Peter B Lillehoj
• 金额: $ 24.44万
• 依托单位: RICE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10666966
• 关键词: Acute; Antibodies; Antigens; Argentina; Biological Assay; Blood; Blood Transfusion; Blood donor; Cardiomyopathies; Chagas Disease; Chronic; Chronic Phase; Collection; Colombia; Country; Data; Detection; Development; Diagnosis; Diagnostic; Disease; Drops; Ecuador; Enzyme-Linked Immunosorbent Assay; Enzymes; Equipment; Exhibits; Generations; Geography; Goals; Guatemala; Healthcare Systems; Heart Arrest; Heart failure; Honduras; Human; Immobilization; Immunoassay; Immunoglobulin G; Individual; Infection; Laboratories; Latin America; Leishmania; Libraries; Life; Magnetism; Measurement; Mexico; Microscopy; Mission; Morbidity - disease rate; National Institute of Allergy and Infectious Disease; Outcome; Pan American Health Organization; Parasitemia; Parasites; Patient-Focused Outcomes; Patients; Performance; Persons; Phase; Process; Proteins; Protocols documentation; Public Health; Reader; Recombinants; Recommendation; Reporter; Research; Resources; Sampling; Sensitivity and Specificity; Serology; Serology test; Serum; Source; Specificity; Symptoms; Techniques; Test Result; Testing; Time; Trypanosoma cruzi; United States; accurate diagnostics; acute infection; antigen detection; chronic infection; cross reactivity; design; detection limit; detection method; detection sensitivity; diagnostic assay; disease transmission; effectiveness evaluation; improved; innovation; mortality; nano; neglected tropical diseases; novel diagnostics; pathogen; prototype; screening

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.

恰加斯病是一种被忽视的热带疾病，是拉丁美洲的地方病，但正日益受到重视。 在美国检测到。恰加斯病是由克氏锥虫 (T. cruzi) 寄生虫引起的 呈现两个阶段：急性期和慢性期。这两个阶段的诊断都具有挑战性 因为患者可能无症状或有非特异性症状。如果不治疗，急性感染会发展为 慢性期，20-40%的患者会出现危及生命的疾病，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出；然而，慢性感染期间的寄生虫血症水平 低于该技术的检测限，使其不适合诊断。因此，诊断 慢性感染的诊断主要依靠抗T血清学检测。 cruzi 抗体，可以持续存在于 受感染者一生的血液。然而，现有的血清学检测容易得出不确定的结论 或由于这些测定中使用的天然克氏锥虫捕获蛋白不足而导致的假阴性/阳性结果 以及 7 个 T. cruzi 离散分型单位 (DTU) 亚型的差异。由于这些原因，世界卫生组织和 泛美卫生组织建议至少使用两种不同的血清学技术进行测试来诊断恰加斯感染。 在美国，这两项测试得出的不一致结果需要将样本转发给 CDC 进行额外测试以确认诊断。这种重复的测试过程占用了大量资源 医疗保健系统的负担和现有恰加斯血清学检测的不良表现可能会导致 由于误诊导致疾病传播和危及生命的疾病增加。因此，本次活动的目的 该项目的目的是开发一种血清学测试，可以准确检测克氏锥虫感染的所有地理差异。 该测定将采用一系列精心设计的重组克氏锥虫抗原，以实现高度特异性 检测所有克氏锥虫亚型，同时与其他病原体不存在交叉反应。理由如下： 拟议的研究得到申请人初步数据的支持，证明产生了 重组克氏锥虫抗原（Tc24），可准确检测抗锥虫。来自多个人的血清中的 cruzi IgG 南美锥虫病流行国家和抗 T 细胞的高灵敏度检测。使用磁电机检测人血清中的 cruzi IgG 免疫测定原型。为实现这一目标，我们将追求以下具体目标： 1) 鉴定用于高特异性检测所有克氏锥虫亚型的重组抗原集合； 2) 开发一种磁免疫分析法，用于高灵敏度和特异性检测克氏锥虫。 这种方法是创新的，因为它结合了一系列精心设计的重组 T. cruzi 抗原，用于检测 T. cruzi 的所有地理亚型，同时与其他抗原不存在交叉反应 用灵敏的磁免疫分析来检测寄生虫，其意义重大，因为它将改善寄生虫的诊断 慢性恰加斯病患者，从而有助于降低与疾病相关的发病率和死亡率。