Point-of-care immunoassay for early diagnosis of pertussis

用于早期诊断百日咳的即时免疫分析

基本信息

批准号：
9302246
负责人：
Amanda Burnham-Marusich
金额：
$ 35.13万
依托单位：
DXDISCOVERY, INC.
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-06-01 至 2019-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9302246
关键词：
Affinity Animal Model Annual Reports Antigen Targeting Antigens Aspirate substance Bedside Testings Bioinformatics Biological Assay Biological Markers Bordetella pertussis Case Study Cells Clinic Clinical Clinical Sensitivity Coughing Country Data Detection Diagnosis Diagnostic Disease Disease Outbreaks Early Diagnosis Early treatment Economics Enzyme-Linked Immunosorbent Assay Epitopes Equipment Evaluation Goals Health Personnel Hospitals Immunoassay Infant Infection Lateral Libraries Measures Modeling Monoclonal Antibodies Morbidity - disease rate Papio Patient Care Patients Performance Pertussis Phase Protein Isoforms Public Health Reproducibility Respiratory Tract Infections Sampling Sensitivity and Specificity Severity of illness Ships Streptococcal Infections Swab Symptoms Target Populations Technology Test Result Testing Time United States Vaccines base clinically relevant commercialization cost design factor A illness length improved innovation large scale production pathogen pediatrician point of care point-of-care diagnostics polyclonal antibody prevent protein aminoacid sequence prototype rapid diagnosis sample collection transmission process urgent care

项目摘要

Project Summary Pertussis is rapidly re-emerging as a serious public health threat in the United States. Despite high vaccine coverage nationally, annual reported cases in the U.S. have been increasing recently, with a 57-year high of 48,000 in 2012. Moreover, reported cases represent a large underestimate of pertussis infections. Diagnosis of early pertussis (catarrhal stage; prior to paroxysmal cough) is particularly challenging because its symptoms are non-specific and because there are no assays that can diagnose pertussis at the point of patient care. There is a critical need to develop improved pertussis diagnostics to fill this gap because pertussis treatment reduces disease severity and duration, but only if treatment begins prior to paroxysmal cough. The goal of this project is to develop a rapid (<15min), point-of-care (POC) immunoassay to detect Bordetella pertussis during early disease. The target population will be infants with the non-specific, respiratory tract infection symptoms of early-stage pertussis. The approach will be detection of B. pertussis antigens from nasopharyngeal (NP) samples by lateral flow immunoassay (LFI). The POC diagnostic that we propose is innovative because it will change the current clinical status quo: a pertussis LFI will give healthcare providers immediate access to actionable and relevant information, which will enable rapid and appropriate patient care. In Phase I, we demonstrated the feasibility of our LFI approach and achieved every milestone of our Phase I Specific Aims. Specifically, we used an innovative bioinformatics-based strategy to develop epitope-specific polyclonal antibodies (pAbs) against a B. pertussis antigen that has both cell-associated and secreted isoforms. We then validated our pAbs for reactivity with both isoforms in sensitive and specific LFI prototypes. The limit of detection of our current pAb-based LFI is 1.6 x 105 CFU, which is well below the typical bacterial burden of infant NP washes (107 to 1010 CFU/ml) or swabs (106 CFU). In Phase II, we will build on our Phase I results and develop an advanced monoclonal antibody (mAb) based LFI commercial diagnostic. We will focus on developing mAbs against the validated biomarker epitopes (Aim 1) and incorporating these mAbs into an LFI with sensitivity and commercialization potential superior to that of the Phase I pAb-based prototypes. We will i) optimize the mAb-based LFI for analytical sensitivity in NP samples (Aim 2), ii) determine clinical sensitivity and specificity at different disease stages in a clinically relevant, baboon infection model (Aim 3), and iii) determine the LFI's limit of detection with patient samples (Aim 4). Together, this data will guide our FDA 510(k) Pre-Submission at the end of Phase II. Successful completion of our milestones will ultimately yield a rapid, affordable, POC immunoassay that will dramatically increase early pertussis diagnosis, which will i) initiate prompt treatment, ii) reduce disease severity and duration, iii) limit outbreaks by preventing unnecessary transmission, and iv) save infant lives.

项目摘要百日咳在美国迅速重新出现是严重的公共卫生威胁。尽管疫苗很高全国范围内，美国的年度报告案件最近正在增加，57年的高度为57年 2012年48,000。此外，报道的病例大大低估了百日咳感染。诊断百日咳早期（卡塔哈尔阶段；阵发性咳嗽之前）特别具有挑战性，因为它的症状是非特异性的，并且因为没有任何可以在患者护理时诊断百日咳的测定。由于百日咳治疗减少疾病的严重程度和持续时间，但前提是在阵发性咳嗽之前开始治疗。该项目的目的是开发快速（<15分钟），护理点（POC）免疫测定法以检测Bordetella 早期疾病期间百日咳。目标人群将是具有非特异性呼吸道的婴儿早期百日咳的感染症状。该方法将是从鼻咽（NP）样品通过侧向流免疫测定（LFI）。我们建议的POC诊断是创新性，因为它将改变当前的临床现状：百日咳LFI将为医疗保健提供者提供立即访问可操作和相关的信息，这将使快速而适当的患者护理能够访问。在第一阶段，我们证明了LFI方法的可行性，并实现了我们第I阶段的每个里程碑具体目标。具体而言，我们使用了创新的基于生物信息学的策略来开发表位特异性与具有细胞相关且分泌的链球菌抗原的多克隆抗体（PAB）同工型。然后，我们验证了我们的PAB在敏感和特定LFI原型中用同工型的反应性。我们当前基于PAB的LFI的检测极限为1.6 x 105 CFU，远低于典型细菌婴儿NP洗涤（107至1010 cfu/ml）或拭子（106 CFU）的负担。在第二阶段，我们将基于我们的阶段结果，并开发基于高级单克隆抗体（MAB） LFI商业诊断。我们将专注于针对经过验证的生物标志物表位的mAB（目标1）并将这些mAb纳入具有敏感性和商业化潜力的LFI中基于I期PAB的原型。我们将）优化基于mAb的LFI，以用于NP样品中的分析灵敏度（AIM 2），ii）在临床相关的不同疾病阶段确定临床敏感性和特异性，狒狒感染模型（AIM 3）和iii）确定LFI使用患者样品的检测极限（AIM 4）。这些数据将共同指导我们的FDA 510（k）在第二阶段结束时进行预选。成功完成我们的里程碑最终将产生快速，负担得起的POC免疫测定法百日咳诊断，这将i）i）开始及时治疗，ii）降低疾病的严重程度和持续时间，iii）限制通过防止不必要的传播来爆发，iv）挽救婴儿生命。