Pathogenesis-Based Diagnostics and Pharmacotherapeutics for PAP

摘要 尽管我们对肺泡蛋白沉积症(PAP)--一种表面活性物质综合征--的了解有了极大的提高 在多种疾病中出现的积聚和呼吸衰竭；在临床上，PAP通常用各种方法来评估 (例如，肺活检)无法识别引起PAP的疾病，并且没有FDA批准的药物来治疗它。一次引发PAP 自身免疫性PAP(APAP)是由GM-CSF自身抗体(GMAbs)介导的，占90%以上 所有的案子。重要的是，虽然多项临床试验和医学文献中越来越多的报告记录了 吸入GM-CSF治疗APAP的有效性、安全性和耐受性，结果衡量标准的使用尚未得到验证 这些患者是监管部门批准的主要障碍。患病率低，未充分利用有效的诊断方法 (导致误诊和漏诊)，对GM-CSF调节表面活性物质的动力学知之甚少 AM的清除构成了药物治疗开发的额外障碍。在前几个资助期，我们 开发了一系列基于发病机制的血液检测，其中包括一种-血清GMAb检测-100%敏感和 是APAP的特异体，现在是APAP诊断的黄金标准。我们还开发了一种干血斑卡片(DBSC) 这项测试的版本-DBSC GMAb测试-并在实验室中对照血清GMAb测试进行了验证。另一个 测试-EC50-GM-CSF信号测试-确定必须添加到肝素化的外源性GM-CSF的量 血液(APAP或对照)刺激GM-CSF信号。最后，我们发现血清中的胆汁酸和自动化 胸部CT扫描的计算机分析(使用卡尺软件)可以用来测量疾病的严重程度和治疗 APAP患者的反应。我们计划检验以下中心假说：推动糖尿病发病机制的介体 APAP为APAP的诊断、治疗性GM-CSF剂量预测、疾病严重程度的卓越检测提供了基础 监测和治疗反应测量。我们的初步数据有力地支持了这一假设。 此外，临床标本、数据和CT扫描的存在增加了拟议研究的可行性 取自最近完成的一例大型(138例APAP患者)随机、双盲、安慰剂对照的临床GM-CSF 治疗试验，这对我们是可用的。在目标1中，我们将评估DBSC-GMAb检测试剂盒对APAP和EC50的诊断价值。 GM-CSF试验预测APAP患者治疗所需的GM-CSF剂量。在目标2中，我们将确定 GM-CSF调节AM清除胆固醇(和表面活性物质)的动力学及Abcg1和STAT5在AM中的作用 这个机制。在目标3中，我们将评估几种与发病相关的生化和放射结果指标。 了解PAP疾病的严重程度和治疗反应。预期结果将验证一项新的测试，以加速和改进 APAP的诊断，评估一项确定患者治疗APAP所需GM-CSF剂量的测试，确定GM-CSF是否 治疗应每天或每隔一周进行，并验证肺部疾病和 APAP的治疗反应。这些预期结果预计将产生重大的积极影响，因为它们 期望通过执业医生改善医疗保健服务，提高人们的生活质量 促进GM-CSF作为一种新的治疗APAP的药物的发展。

ABSTRACT Despite our vastly improved understanding of pulmonary alveolar proteinosis (PAP) – a syndrome of surfactant accumulation and respiratory failure that occurs in multiple diseases; clinically, PAP is usually evaluated using methods (e.g., lung biopsy) unable to identify the PAP-causing disease and no drug is FDA-approved to treat it. One PAP-causing disease, autoimmune PAP (aPAP), is mediated by GM-CSF autoantibodies (GMAbs) and accounts for more than 90% of all cases. Importantly, while multiple clinical trials and an increasing of reports in the medical literature document the efficacy, safety and tolerability of inhaled GM-CSF therapy of aPAP, the use of outcome measures not yet validated in this patient population is a major barrier to regulatory approval. Low prevalence, underuse of effective diagnostics (leading to misdiagnosis and under-detection), and little knowledge of the kinetics by which GM-CSF regulates surfactant clearance by AMs comprise additional hurdles to pharmacotherapeutic development. In the prior funding periods, we developed a panel of pathogenesis-based blood tests including one – the Serum GMAb Test – that is 100% sensitive and specific for aPAP and is now the ‘gold standard’ for aPAP diagnosis. We also developed a dried blood spot card (DBSC) version of this test – the DBSC GMAb Test – and validated it in the laboratory against the Serum GMAb Test. Another test – the EC50-GM-CSF Signaling Test – identifies the amount of exogenous GM-CSF that must be added to heparinized blood (aPAP or control) to stimulate GM-CSF signaling. Finally, we found that serum cholestenoic acid and automated computer analysis of chest CT scans (using CALIPER software) can be used to measure disease severity and treatment responses in aPAP patients. We plan to test the following central hypothesis: mediators driving the pathogenesis of aPAP provide the basis for outstanding tests for diagnosis of aPAP, therapeutic GM-CSF dose-prediction, disease severity monitoring, and treatment response measurement. This hypothesis is strongly supported by our Preliminary Data. Further, the feasibility of the proposed research is increased by the existence of clinical specimens, data, and CT scans from a recently completed large (138 aPAP patient) randomized, double-blinded, placebo controlled clinical GM-CSF therapy trial, which are available to us. In Aim 1 we will evaluate DBSC-GMAb test kit for diagnosis of aPAP and EC50- GM-CSF Test for predicting the dose of GM-CSF patients will require as therapy of aPAP. In Aim 2, we will determine the kinetics by which GM-CSF regulates cholesterol (and surfactant) clearance by AMs and the role of ABCG1 and STAT5 in this mechanism. In Aim 3, we will evaluate several pathogenesis-related biochemical and radiological outcome measures of PAP disease severity and treatment responses. Expected results will validate a new test to accelerate and improve the diagnosis of aPAP, evaluate a test to determine the GM-CSF dose patients require as therapy aPAP, determine if GM-CSF therapy should be administered daily or on alternating weeks, and validate new outcome measures of lung disease and treatment responses in aPAP. These expected results are anticipated to have significant positive impact because they are expected to lead to improved healthcare delivery by practicing physicians, improve the quality of life for people living with PAP, and accelerate the pharmacotherapeutic development of GM-CSF as a new treatment for aPAP patients.