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.

查加斯病是一种被忽视的热带疾病，对拉丁美洲是内在的，但越来越多 在美国检测到。 Chagas病是由Cruzi（T. Cruzi）寄生虫和 分为两个阶段：急性期和慢性期。两个阶段的诊断都具有挑战性 因为患者可能是渐近的或具有非特异性症状。如果未经治疗，急性感染会发展为 慢性阶段有20-40％的患者会出现威胁生命的疾病，包括心肌病，心脏 失败和心脏骤停。 可以通过显微镜检测急性感染。但是，慢性感染期间的寄生虫血症水平 下降到检测到该技术的极限之下，使其不适合诊断。因此，诊断 慢性感染的主要依赖于抗T的血清学检测。克鲁兹抗体，可以持续 在感染者的整个生命中的血液。但是，现有的血清学测试容易确定 或由于这些测定中使用的天然T. cruzi捕获蛋白不足而导致的假阴性/阳性结果 以及七个T. cruzi离散键入单元（DTU）亚型的差异。由于这些原因，谁是谁和 PAHO建议使用至少两种不同的血清学技术进行诊断室内感染的测试。 在美国，从这两项测试中获得的不一致的结果要求将样本转发到 CDC进行其他测试以确认诊断。这个重复的测试过程不可能是重要的资源 医疗保健系统的负担以及现有Chagas血清学检查的不良表现可能导致 疾病传播和威胁生命的疾病增加。因此，这个目的 项目是开发一种可以准确检测到克鲁兹感染的所有地理方差的血清学测试。 该测定法将采用精心设计的重组T. cruzi抗原的集合来高度具体 在与其他病原体没有交叉反应性的同时，检测所有克氏菌亚型。理由 申请人的初步数据支持了拟议的研究，证明了生成 可以准确检测抗T的重组T. cruzi抗原（TC24）。来自多个人类血清中的Cruzi IgG Chagas-Endimic国家和对抗T的高度敏感检测。使用Magneto的人血清中的Cruzi IgG 免疫测定原型。为了实现这一目标，我们将追求以下特定目标： 1）确定一组重组抗原，用于检测具有高特异性的所有T. cruzi亚型； 2）开发一种用于高灵敏度和特异性检测的磁铁免疫测定。 这种方法具有创新性，因为它结合了精心设计的重组T的使用。 Cruzi抗原用于检测T. cruzi的所有地理亚型，同时与其他人没有交叉反应性 具有敏感磁铁免疫测定的寄生虫，这很重要，因为它将改善 患有慢性chagas病的患者，从而有助于降低与疾病相关的发病率和死亡率。