需要生物标志物来支持对帕金森病（PD）的准确诊断。脑脊液（CSF）已经成为寻找神经退行性生物标志物的成功生物体液，现代高度敏感的多重检测方法使发现性研究成为可能。我们采用大规模多重接近扩增（PEA）方法，旨在发现新的诊断性蛋白质生物标志物，以实现 PD 与正常对照组以及非典型帕金森病性疾病（APD）之间的准确鉴别。我们分析了来自 PD、皮层基底综合征（CBS）、进行性核上性麻痹（PSP）、多系统萎缩症患者和对照组的 CSF 样本，使用 Olink PEA 面板进行了分析。本研究使用了三个队列分别为 192, 88 和 36 例。所有样本均在心血管 II、肿瘤学 II 和代谢学 PEA 面板上运行。我们的分析结果显示测试和验证 PD 队列中 CSF 的 26 个和 39 个蛋白质在表达上分别与对照组存在差异。其中 6 个蛋白质在这两个队列中都发生了变化。Midkine（MK）在 PD 患者中增加的效应最为显著，结果经 ELISA 验证。另外，DOPA 脱羧酶（DDC），一种催化多巴胺（L-3,4-二羟基苯丙氨酸）脱羧形成多巴胺的酶，也在 PD 中增加，与多巴胺能治疗有很强的相关性。此外，Kallikrein 10 在 APD 与 PD 以及对照组之间发生了特异性变化，但在 PD 与对照组之间没有变化。Wnt 抑制因子 1 在两个独立队列中皮层基底综合征和进行性核上性麻痹患者中稳定下调。我们通过大规模 PEA 方法在 PD 患者的 CSF 中确定了潜在的新型 PD 诊断标志物，尤其是 MK 和 DDC。 © 2023. 上海交通大学医学院附属瑞金医院。

There is a need for biomarkers to support an accurate diagnosis of Parkinson's disease (PD). Cerebrospinal fluid (CSF) has been a successful biofluid for finding neurodegenerative biomarkers, and modern highly sensitive multiplexing methods offer the possibility to perform discovery studies. Using a large-scale multiplex proximity extension assay (PEA) approach, we aimed to discover novel diagnostic protein biomarkers allowing accurate discrimination of PD from both controls and atypical Parkinsonian disorders (APD).CSF from patients with PD, corticobasal syndrome (CBS), progressive supranuclear palsy (PSP), multiple system atrophy and controls, were analysed with Olink PEA panels. Three cohorts were used in this study, comprising 192, 88 and 36 cases, respectively. All samples were run on the Cardiovascular II, Oncology II and Metabolism PEA panels.Our analysis revealed that 26 and 39 proteins were differentially expressed in the CSF of test and validation PD cohorts, respectively, compared to controls. Among them, 6 proteins were changed in both cohorts. Midkine (MK) was increased in PD with the strongest effect size and results were validated with ELISA. Another most increased protein in PD, DOPA decarboxylase (DDC), which catalyses the decarboxylation of DOPA (L-3,4-dihydroxyphenylalanine) to dopamine, was strongly correlated with dopaminergic treatment. Moreover, Kallikrein 10 was specifically changed in APD compared with both PD and controls, but unchanged between PD and controls. Wnt inhibitory factor 1 was consistently downregulated in CBS and PSP patients in two independent cohorts.Using the large-scale PEA approach, we have identified potential novel PD diagnostic biomarkers, most notably MK and DDC, in the CSF of PD patients.© 2023. Ruijin Hospital, Shanghai Jiao Tong University.