Gene Expression Biomarkers for Diagnosis of Lyme Disease

描述（由申请方提供）：莱姆病是美国最常报告的蜱媒传染病，其发病率和范围都在增加。莱姆病的早期诊断和治疗对于防止疾病进展和后遗症至关重要。目前的实验室诊断主要是血清学测定，它们在一些关键领域失败。它们在早期莱姆病中特异性不足，不敏感，不能确定治疗反应。更重要的是，因为血清学测定是基于抗体的存在，它们不能区分活动性感染和免疫记忆，由于先前的，解决感染伯氏疏螺旋体。我们需要新的范例和分析来解决我们诊断能力中的这些差距。在这里，我们提出了一种新的方法。我们将利用差异基因表达分析来鉴定对B的签名应答。莱姆病患者血液中的伯氏螺旋体，长期目标是开发一种可靠的基于基因的活动性感染诊断测试。具体而言，我们建议：1）使用微阵列分析来鉴定从患有活动性、培养证实的莱姆病的患者分离的外周血单核细胞（PBMC）中差异表达的基因，并将结果与来自健康供体的PBMC进行比较; 2）鉴定一组预测B的cDNA基因。与其他常见的血液传播细菌病原体的感染相反，使用预测选择的监督学习方法来评估伯氏螺旋体感染; 3）评估鉴定为B的基因的表达水平。本研究通过实时RT-PCR在症状消退的患者中标准抗生素治疗后获得的成对急性和恢复期患者样品中检测伯氏特异性指示基因。这将提供成功治疗的患者随时间推移的基因表达信息，并应定义活动性（而不是消退的）B的特征基因子集。伯氏感染这些研究预计将导致确定一组明确的指示基因，这些基因在活动性莱姆病患者中受到显著和独特的调控，而不是已经成功地用抗生素治疗的患者或其他常见的血液传播细菌感染的个体。一旦鉴定，该分类器基因子集可作为开发活性B的敏感和特异性诊断测试的基础。伯氏感染 公共卫生相关性：莱姆病是美国最常报道的蜱传疾病，由螺旋体伯氏疏螺旋体感染引起，目前的诊断基于血清学检测，其缺乏灵敏度和特异性，尤其是在早期疾病中，并且不能区分活动性感染和先前的已消退的B感染。burgdorferi。拟议的研究预计将导致确定一组明确的指示基因，这些基因在活动性莱姆病患者中受到显著和独特的调控，而不是其他常见的血液传播细菌感染患者或患有经抗生素治疗的已消退莱姆病的个体，无论是否有持续症状。一旦鉴定，该分类器基因的子集可用作开发用于活性B的敏感且特异的基于基因的诊断测试的基础。伯氏感染

DESCRIPTION (provided by the applicant): Lyme disease is the most frequently reported tick-borne infectious disease in the United States and both its incidence and range are increasing. Early diagnosis and treatment of Lyme disease is critical to prevent disease progression and sequellae. Current laboratory diagnostics are primarily serologic assays and they fail in a number of key areas. They are insufficiently specific, not sensitive in early Lyme disease and cannot determine treatment response. More importantly, because serological assays are based on the presence of antibodies, they are incapable of discriminating between active infection and immunological memory due to prior, resolved infection with Borrelia burgdorferi. New paradigms and assays are needed to address these gaps in our diagnostic capabilities. Here we propose a new approach. We will utilize differential gene expression analysis to identify a signature response to B. burgdorferi in the blood of Lyme disease patients, with the long-term objective of developing a reliable gene-based diagnostic test for active infection. Specifically we propose to: 1) use microarray analysis to identify genes differentially expressed in peripheral blood mononuclear cells (PBMCs) isolated from patients with active, culture-confirmed Lyme disease and compare the results to PBMCs from healthy donors; 2) identify a set of discriminator genes predictive of B. burgdorferi infection, as opposed to infection by other common blood-borne bacterial pathogens, using a supervised learning approach of predictor selection; 3) assess expression levels of genes identified as B. burgdorferi-specific indicator genes by real-time RT-PCR in paired acute and convalescent patient samples obtained following standard antibiotic treatment in patients with resolution of symptoms. This will provide information on the gene expression over time in successfully-treated patients and should define a subset of discriminator genes characteristic of active, as opposed to resolved, B. burgdorferi infection. These studies are expected to result in the identification of a defined set of indicator genes which are significantly and uniquely regulated in patients with active Lyme disease as opposed to patients that have been successfully treated with antibiotics or individuals with other common blood-borne bacterial infections. Once identified, this subset of classifier genes can serve as the basis for development of a sensitive and specific diagnostic test for active B. burgdorferi infection. PUBLIC HEALTH RELEVANCE: Lyme disease, the most frequently reported tick-borne disease in the United States, is caused by infection with the spirochete Borrelia burgdorferi and diagnosis is currently based on serological tests which lack sensitivity and specificity, especially in early disease, and do not discriminate between active infection and prior, resolved infection with B. burgdorferi. The proposed studies are expected to result in the identification of a defined set of indicator genes which are significantly and uniquely regulated in patients with active Lyme disease as opposed to patients with other common blood-borne bacterial infections or individuals with antibiotic-treated, resolved Lyme disease with or without ongoing symptoms. Once identified, this subset of classifier genes could be employed as the basis for development of a sensitive and specific gene-based diagnostic test for active B. burgdorferi infection.