Pathogenesis-Based Diagnostics and Pharmacotherapeutics for PAP

摘要 尽管我们对肺泡蛋白沉积症（PAP）的认识有了很大的提高， 在多种疾病中发生的积聚和呼吸衰竭;临床上，PAP通常使用方法进行评估 (e.g.,肺活检）不能识别PAP引起的疾病，并且没有药物被FDA批准用于治疗它。 自身免疫性PAP（aPAP）是由GM-CSF自身抗体（GMAb）介导的疾病，占 所有案件。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，使用尚未验证的结局指标， 该患者群体是监管批准的主要障碍。流行率低，有效诊断使用不足 （导致误诊和检测不足），以及对GM-CSF调节表面活性剂的动力学知之甚少 AM的清除是药物开发的额外障碍。在过去的融资周期中，我们 开发了一组基于病因的血液检测，包括血清GMAb检测，其灵敏度为100%， 特异于aPAP，现在是aPAP诊断的“金标准”。我们还开发了干血斑卡（DBSC） 该测试的版本-DBSC GMAb测试-并在实验室中针对血清GMAb测试对其进行验证。另一 试验-EC 50-GM-CSF信号传导试验-确定必须加入肝素化的细胞中的外源性GM-CSF的量。 血液（aPAP或对照）以刺激GM-CSF信号传导。最后，我们发现，血清中的β-烯酸和自动 胸部CT扫描的计算机分析（使用CALIPER软件）可用于衡量疾病的严重程度和治疗 aPAP患者的反应。我们计划测试以下中心假设：介质驱动的发病机制， aPAP为aPAP的诊断、治疗性GM-CSF剂量预测、疾病严重程度的突出测试提供了基础。 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 来自最近完成的大型（138例aPAP患者）随机、双盲、安慰剂对照临床GM-CSF 治疗试验，这是我们可以得到的。在目标1中，我们将评估DBSC-GMAb检测试剂盒用于诊断aPAP和EC 50- GM-CSF试验可预测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（和表面活性剂）的动力学以及ABCG 1和STAT 5在 这个机制。在目标3中，我们将评估几种与发病机制相关的生化和放射学结局指标 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，以加速和改善 aPAP的诊断，评估测试以确定患者需要作为aPAP治疗的GM-CSF剂量，确定GM-CSF是否 治疗应每天或每隔一周进行，并验证肺部疾病的新结果指标， aPAP中的治疗反应。这些预期结果预计将产生重大的积极影响，因为它们是 预计将导致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作为治疗aPAP的新药物的开发。

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.