Direct visualization assay for detection of B. burgdorferi in early Lyme Disease

描述（由申请人提供）：莱姆病是一种由伯氏疏螺旋体引起的蜱传感染，已扩大到美国每年约30万例。目前批准的免疫反应测试是次优的，经常在疾病早期给出阴性结果。本应用程序中概述的研究是开发一种直接可视化伯氏疏螺旋体的诊断血液测试。这种测试将允许更早地发现——从而更好地治疗——并可用于监测有症状的患者对治疗的反应。RareCyte Inc.是一家早期生命科学公司，致力于血液中稀有细胞的表征和提取，该公司拥有一种高度工程化的富集技术，该技术基于管、浮子和收集机制，可以根据密度对血液中的细胞和病原体进行分层。利用这项技术，已经开发出一种原型检测方法，通过免疫荧光显微镜在培养的螺旋体、血液样本和早期莱姆病患者的血液中直接显示伯氏疏螺旋体抗原阳性生物体。该项目的长期目标是使莱姆病的敏感和特异性的直接可视化实验室测试商业化，并证明其临床实用性。我们假设直接检测可视化试验能够在低检测限下可靠、特异地鉴定血液中的螺旋体伯氏疏螺旋体。具体而言，我们将：(1)优化和验证该分析的技术性能，并在每mL 2个生物体时达到80%的目标灵敏度；(2)评估背景信号并对来自非流行病受试者的血液样本进行峰值研究，以确定具有90%特异性的阳性截止值，并建立85%的实验室内和实验室间重复性；(3)在一项包括莱姆病抗生素治疗前、期间和之后患者样本的初步研究中，调查该检测方法的临床性能特征。我们期望在一项II期多实验室盲法临床验证研究中实现一种优化和验证的检测方法，该方法具有明确的评分标准和对照试剂，可直接检测血液中的伯氏疏螺旋体，以证明与目前的两层检测方法相同或性能更好。该检测方法的市场与莱姆病的高发病率相当，估计每年进行100万至200万次检测。RareCyte将制定许可和合作战略，为FDA 510(k)批准提供试剂盒和仪器。

DESCRIPTION (provided by applicant): Lyme disease, a tick-borne infection caused by the spirochete Borrelia burgdorferi, has expanded to an estimated 300,000 US cases per year. Currently approved tests of immune response are sub-optimal and often give negative results early in the disease. The research outlined in this application is to develop a diagnostic blood test that directly visualizes B. burgdorferi. This test will allow earlier detection - and hence beter treatment - and could be used to monitor symptomatic patients for response to treatment. RareCyte Inc., an early-stage life science company dedicated to the characterization and retrieval of rare cells in blood, has a highly engineered enrichment technology based on a tube, float and collection mechanism that can stratify cells and pathogens in the blood by density. Using this technology, a prototype assay has been developed that has demonstrated direct visualization of B. burgdorferi antigen- positive organisms by immunofluorescence microscopy in cultured spirochetes, spiked- in blood samples, and in blood of patients with early Lyme disease. The long-term goal of this project is to make commercially available a sensitive and specific direct visualization laboratory test for Lyme disease with demonstrated clinical utility. We hypothesize that the direct detection visualization assay will reliably and specifically identif Borrelia spirochetes in the blood at a low limit of detection. Specifically, we will: (1) optimize nd validate technical performance of the assay and achieve target sensitivity of 80% at 2 organisms per mL; (2) evaluate background signal and perform a spike-in study in blood samples from non-endemic subjects to define a positive cut-off with 90% specificity, and establish intra- and inter-laboratory reproducibility of 85%; (3) investigate clinical performance characteristics of the assay in a pilot study to include samples from patients before, during and after Lyme disease antibiotic treatment. We expect to achieve an optimized and validated assay with defined scoring criteria and control reagents to directly detect B. burgdorferi in blood for ue in a Phase II multi-laboratory, blinded clinical validation study to demonstrate equivalence or improved performance over current two-tiered testing. The market for the assay parallels the high incidence of Lyme disease, and is estimated at between 1 and 2 million tests per year. RareCyte will develop licensing and partnering strategies to provide kits and instruments for FDA 510(k) approval.