NOVEL BIOMARKERS FOR MECHANISTIC DIAGNOSIS OF THE ANTIPHOSPHOLIPID SYNDROME

描述（申请人提供）：本申请解决了挑战主题03-HL-101*，以识别和验证血液和血管功能障碍的诊断和治疗反应的临床相关、可量化的生物标志物-特别是抗磷脂综合征（APS），一种自身免疫性血栓形成疾病，据报道约10%的静脉血栓栓塞性疾病患者是由APS引起的，死亡和发病的主要原因之一，导致约300，000例住院和50例，目前，每年有10000人死亡，APS是通过25年前开发的抗磷脂抗体（aPL）的经验性测试来诊断的-aPL免疫测定法来源于“生物假阳性梅毒”。测试和凝血抑制剂称为狼疮抗凝剂（LA）。这些检测不能检测疾病机制，特异性、灵敏度和预测值较差。此外，由于其局限性，目前的测试不允许诊断，直到患者已经有至少一个不良临床事件。然而，最近在APS的病理生理学知识方面取得了重大进展，这可能对诊断产生重大影响。其中包括：1）机制的鉴定-抗体介导的强效血管和胎盘抗凝蛋白膜联蛋白A5的破坏-已经被定义，为此我们开发了一种稳健的功能测定，膜联蛋白A5抗性（A5 R）测定，在小的明确定义的组的几项盲法研究中得到验证，其中该机制在目前定义为患有APS的所有患者中的至少一半中一致地被鉴定。2)鉴定自身抗体的特异性靶表位-β-2-糖蛋白I的结构域I（D1）-也与血栓形成和妊娠丢失风险显著增加相关。抗D1 IgG的测定已被证明与A5 R相关。 因此，本授权申请的重点是验证血栓形成APS机制的这2种新的相关生物标志物：1）膜联蛋白A5抗性（A5 R）测定和2）β-2-糖蛋白I（抗D1）结构域I抗体的免疫测定，这是一种与膜联蛋白A5抗性相关的表位。蒙蒂菲奥里医疗中心（MMC）是纽约布朗克斯的主要学术医疗中心，为美国最贫穷的城市县之一的150万居民提供服务。MMC拥有患者基础和资源，可在2年挑战补助金时间框架内成功完成这些研究。我们目前每年对疑似患有APS的患者进行超过2，700次诊断性aPL检查。MMC的计算机化健康记录系统，匿名样本的访问，实验室设施，以及我们对APS的研究基础，使我们能够在2年的时间内完成这个项目。该项目可能会导致重要的新机制生物标志物的验证，这些生物标志物可能对改善APS患者的诊断和治疗产生直接影响，并实现ARRA的经济意图。 公共卫生相关性：本申请旨在解决挑战主题03-HL-101*，以识别和验证血液和血管功能障碍（特别是抗磷脂综合征（APS））诊断和治疗反应的临床相关、可量化生物标志物。 因此，这项拨款申请的重点是验证这2个新的和相关的生物标志物， 血栓形成APS机制：1）膜联蛋白A5抗性（A5 R）测定和2）针对β-2-糖蛋白I的结构域I（抗D1）的抗体的免疫测定，所述结构域I是与膜联蛋白A5抗性相关的表位。

DESCRIPTION (provided by applicant): This application addresses Challenge Topic 03-HL-101* to identify and validate clinically relevant, quantifiable biomarkers of diagnostic and therapeutic responses for blood and vascular dysfunction - specifically, the antiphospholipid syndrome (APS) an autoimmune thrombotic condition that is reported to be responsible for ~10% of patients with venous thromboembolic disease, one of the leading causes of mortality and morbidity that results in ~ 300,000 hospitalizations and 50,000 fatalities annually APS is currently diagnosed through empirical tests for antiphospholipid (aPL) antibodies that were developed over 25 years ago - the aPL immunoassays which were derived from the "biologic false positive syphilis" test and a coagulation inhibitor known as the lupus anticoagulant (LA). These assays do not test disease mechanisms and have poor specificities and sensitivities and predictive values. Moreover, because of their limitations, the current tests do not permit diagnosis until after patients have already had at least one adverse clinical event. However, there have been significant recent advances in knowledge of the pathophysiology of APS that are likely to have a major impact on diagnosis. These include: 1) Identification of a mechanism - the antibody-mediated disruption of the potent vascular and placental anticoagulant protein, annexin A5 - has been defined, for which we developed a robust functional assay, the annexin A5 resistance (A5R) assay, validated in several blinded studies of small well defined groups, wherein this mechanism is consistently identified in at least half of all patients currently defined as having APS. 2) Identification of a specific target epitope for the autoantibodies - domain I (D1) of beta-2-glycoprotein I - that also correlates with significantly increased risks of thrombosis and pregnancy losses. The assay for anti-D1 IgG has been shown to correlate with A5R. This grant application is therefore focused on validating these 2 new and related biomarkers for a thrombogenic APS mechanism: 1) the annexin A5 resistance (A5R) assay and 2) an immunoassay for antibodies to domain I of beta-2-glycoprotein I (anti-D1), an epitope that correlates with Annexin A5 resistance. Montefiore Medical Center (MMC) is the major academic medical center in Bronx, NY that serves the 1.5 million residents of one of the poorest urban counties in the US. MMC has the patient base and resources for successful completion of these studies within the 2 year Challenge Grant time frame. We currently perform over 2,700 diagnostic aPL panels annually on patients suspected of having APS. MMC's computerized health record system, access to anonymized samples, laboratory facilities, and our research base on APS, ideally position us to complete this project over the 2 year time frame. This project is likely to result in validation of significant new mechanistic biomarkers that are likely to have a direct impact on improving the diagnosis and treatment of patients with APS and also fulfill the economic intents of the ARRA. PUBLIC HEALTH RELEVANCE: This application addresses Challenge Topic 03-HL-101* to identify and validate clinically relevant, quantifiable biomarkers of diagnostic and therapeutic responses for blood and vascular dysfunction - specifically, the antiphospholipid syndrome (APS). This grant application is therefore focused on validating these 2 new and related biomarkers for a thrombogenic APS mechanism: 1) the annexin A5 resistance (A5R) assay and 2) an immunoassay for antibodies to domain I of beta-2-glycoprotein I (anti-D1), an epitope that correlates with Annexin A5 resistance.