Background: Parkinson’s disease (PD) is a neurodegenerative disease characterized by intracellular α-synuclein (α-Syn) deposition. Alternation of the α-Syn expression level in plasma or erythrocytes may be used as a potential PD biomarker. However, no studies have compared their prognostic value directly with the same cohort. Methods: The levels of α-Syn in plasma and erythrocytes, obtained from 45 PD patients and 45 control subjects, were measured with enzyme-linked immunosorbent assay. Then, correlation and receiver operating characteristic curve (ROC) analysis were performed to characterize the predictive power of erythrocytic and plasma α-Syn. Results: Our results showed that α-Syn expression levels in both plasma and erythrocytes were significantly higher in PD patients than in control subjects (823.14 ± 257.79 vs. 297.10 ± 192.82 pg/mL, p < 0.0001 in plasma; 3,104.14 ± 143.03 vs. 2,944.82 ± 200.41 pg/mL, p < 0.001 in erythrocytes, respectively). The results of the ROC analysis suggested that plasma α-Syn exhibited better predictive power than erythrocytic α-Syn with a sensitivity of 80.0%, specificity of 97.7%, and a positive predictive value of 77.8%. The expression level of plasma α-Syn correlated well with the age of patients, H-Y stage, MoCA scale, and UPDRS motor scale. On the contrary, there was no correlation between erythrocytic α-Syn level and clinical parameters in this study. Conclusion: Our results suggest that plasma α-Syn could be a specific and sensitive potential diagnostic biomarker for PD.

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血浆和红细胞 α-突触核蛋白对帕金森病诊断潜力的比较研究

背景：帕金森病（PD）是一种以细胞内α-突触核蛋白（α-Syn）沉积为特征的神经退行性疾病。血浆或红细胞中 α-Syn 表达水平的变化可用作潜在的 PD 生物标志物。然而，没有研究直接将它们的预后价值与同一队列进行比较。方法：采用酶联免疫吸附法测定45例PD患者和45例对照者血浆和红细胞中α-Syn的含量。然后，进行相关性和受试者工作特征曲线 (ROC) 分析以表征红细胞和血浆 α-Syn 的预测能力。结果：我们的结果显示，PD 患者血浆和红细胞中的 α-Syn 表达水平显着高于对照组（823.14 ± 257.79 vs. 297.10 ± 192.82 pg/mL，p < 0.0001 在血浆中；3,104.14 ± 143.03 与 2,944.82 ± 200.41 pg/mL，分别在红细胞中 p < 0.001）。ROC分析结果表明，血浆α-Syn比红细胞α-Syn具有更好的预测能力，敏感性为80.0%，特异性为97.7%，阳性预测值为77.8%。血浆α-Syn的表达水平与患者年龄、HY分期、MoCA量表和UPDRS运动量表相关。相反，本研究中红细胞 α-Syn 水平与临床参数之间没有相关性。结论：我们的结果表明血浆 α-Syn 可能是 PD 的特异性和敏感的潜在诊断生物标志物。ROC分析结果表明，血浆α-Syn比红细胞α-Syn具有更好的预测能力，敏感性为80.0%，特异性为97.7%，阳性预测值为77.8%。血浆α-Syn的表达水平与患者年龄、HY分期、MoCA量表和UPDRS运动量表相关。相反，本研究中红细胞 α-Syn 水平与临床参数之间没有相关性。结论：我们的结果表明血浆 α-Syn 可能是 PD 的特异性和敏感的潜在诊断生物标志物。ROC分析结果表明，血浆α-Syn比红细胞α-Syn具有更好的预测能力，敏感性为80.0%，特异性为97.7%，阳性预测值为77.8%。血浆α-Syn的表达水平与患者年龄、HY分期、MoCA量表和UPDRS运动量表相关。相反，本研究中红细胞 α-Syn 水平与临床参数之间没有相关性。结论：我们的结果表明血浆 α-Syn 可能是 PD 的特异性和敏感的潜在诊断生物标志物。相反，本研究中红细胞 α-Syn 水平与临床参数之间没有相关性。结论：我们的结果表明血浆 α-Syn 可能是 PD 的特异性和敏感的潜在诊断生物标志物。相反，本研究中红细胞 α-Syn 水平与临床参数之间没有相关性。结论：我们的结果表明血浆 α-Syn 可能是 PD 的特异性和敏感的潜在诊断生物标志物。