Profiling Plasma Unbound Free Fatty Acids for Early Detection of Stroke

描述（由申请人提供）：需要新的诊断测试来早期检测急性中风。血浆游离脂肪酸（FFA）升高是中风的早期标志物，但目前测量FFA的方法太慢，无法用于中风检测。相比之下，使用FFAu特异性荧光探针可以在几秒钟内完成血浆FFA的未结合分数（FFAu）的测量。在拟议的I期研究中，将使用对血浆FFAu谱变化敏感的探针开发用于中风检测的快速测试。这项工作将扩大初步调查，证明中风患者和模拟使用荧光标记的大鼠肠脂肪酸结合蛋白的突变体制成的FFAu探针之间的显着歧视。拟议研究的具体目的是（1）开发新探针，以提高FFAu分析准确性并改善诊断性能，以及（2）使用急性卒中转化研究专门项目（SPOTRIAS）库中的样本验证卒中多探针检测的性能。在目标1中，一组新的花生四烯酸，亚麻酸，二十二碳六烯酸，肉豆蔻酸特异性探针将进行表征和测试的分析精度使用模型FFAu混合物。这些探针将与对硬脂酸盐、油酸盐、亚油酸盐、棕榈酸盐和棕榈油酸盐具有特异性的先前探针组一起使用，以确定33例卒中患者和22例拟态患者的血浆FFAu谱。使用线性判别分析，中风分类器将从FFAu配置文件和探针响应的集合中构建。突变体探针文库的高通量筛选将用于开发额外的探针，这将能够进一步提高谱分析的准确性。在目标2中，目标1中开发的分类器将使用来自65名中风患者的一组新的血浆样本和来自SPOTRIAS存储库的45个模拟物进行验证。将在不了解患者诊断的情况下测量样本并将其分类为卒中或假性卒中。受试者工作特征曲线将用于在患者诊断结果显示后评估诊断性能。最后，将从所有165个样本的合并探针数据生成新的分类器。这个新的分类器将在第二阶段用更大的样本集进行测试。 公共卫生相关性：中风的早期诊断对于有效的治疗干预至关重要，但目前尚无中风的快速检测方法。为了满足这一临床需求，将开发一种快速准确的检测血液中脂肪酸谱的方法，用于缺血性和出血性卒中的早期检测。使用这种测试可能会减少缺血性中风的神经损伤，减少诊断和治疗中风患者所需的时间。

DESCRIPTION (provided by applicant): New diagnostic tests are needed for the early detection of acute stroke. Elevated plasma free fatty acids (FFA) are an early marker of stroke, but current methods to measure FFA are too slow to be used for stroke detection. In contrast, measurements of the unbound fraction of plasma FFA (FFAu) can be completed in seconds using FFAu-specific fluorescent probes. In the proposed Phase I study, a rapid test for stroke detection will be developed using probes sensitive to changes in the plasma FFAu profile. This work will extend preliminary investigations that demonstrated significant discrimination between stroke patients and mimics using FFAu probes made from fluorescently labeled mutants of rat intestinal fatty acid binding protein. The specific aims of the proposed study are to (1) develop new probes that will enhance FFAu profiling accuracy and improve diagnostic performance and (2) validate the performance of the multiple-probe test for stroke with samples from the Specialized Programs of Translational Research in Acute Stroke (SPOTRIAS) repository. In Aim 1, a new set of probes specific for arachidonate, linolenate, docosahexaenoate, and myristate will be characterized and tested for profiling accuracy use model FFAu mixtures. These probes will be used with a previous probe set with specificities for stearate, oleate, linoleate, palmitate, and palmitoleate to determine the plasma FFAu profiles in 33 stroke patients and 22 mimics. Using linear discriminant analysis, stroke classifiers will be constructed from the FFAu profiles and from the set of probe responses. High-throughput screening of libraries of mutant probes will be used to develop additional probes that will enable further improvements in profiling accuracy. In Aim 2, the classifiers developed in Aim 1 will be validated with a new set of plasma samples from 65 stroke patients and 45 mimics from the SPOTRIAS repository. Samples will be measured and classified as stroke or mimic without knowledge of the patient diagnoses. Receiver operating characteristic curves will be used to assess diagnostic performance after the patient diagnoses are revealed. Finally, a new classifier will be generated from the pooled probe data for all 165 samples. This new classifier will be tested in Phase II with a larger sample set. PUBLIC HEALTH RELEVANCE: The early diagnosis of stroke is critical for effective therapeutic intervention, yet no rapid test for stroke is available. To meet this clinical need, a rapid and accurate test that determines the profile of fatty acids in blood will be developed for the early detection of ischemic and hemorrhagic stroke. The use of this test would potentially reduce neurological damage from ischemic stroke by reducing the time required to diagnose and treat stroke patients.