title: Detection of α-synuclein oligomers in red blood cells as a potential biomarker of Parkinson's disease.
abstract: Parkinson's disease (PD) is a neurodegenerative disorder characterized by intracellular α-synuclein (α-syn) deposition. Alterations in α-syn levels in cerebrospinal fluid (CSF) and plasma of PD patients have been thought to be potential PD biomarkers; however, contamination arising from hemolysis often influences the accuracy of detecting α-syn levels in the CSF and plasma. In this study, α-syn oligomer levels in red blood cells (RBCs) obtained from 100 PD patients, 22 MSA patients, and 102 control subjects were measured by enzyme-linked immunosorbent assay. We showed that the ratio of α-syn oligomer/total RBC protein was higher in PD patients than in controls (29.0±19.8 ng/mg vs. 15.4±7.4 ng/mg, P<0.001). The area under the receiver operating characteristic curve (AUC) indicated a sensitivity of 79.0%, specificity of 64.7% and a positive predictive value of 68.7%, with an AUC of 0.76 for increased α-syn oligomer/total RBC protein ratio. However, there was no correlation between RBC α-syn oligomer levels and age at onset, disease duration, age, UPDRS motor scale score or progression of motor degeneration in PD patients. The ratio of RBC α-syn oligomer/total protein was also higher in MSA patients than in controls (22.9±13.9 ng/mg vs. 15.4±7.4 ng/mg, P<0.001). However, no significant difference was found for α-syn oligomer/total protein ratio between PD and MSA (29.0±19.8 ng/mg vs. 22.9±13.9 ng/mg, P>0.05). The present results suggest that the RBC α-syn oligomer/total protein ratio can be a potential diagnostic biomarker for PD.
authors.affiliation: Center for Neurodegenerative Disease, Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, #6 Tian Tan Xi Li Street, 100050 Beijing, China. Electronic address: minnie02@sina.com.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Neurobiology, Xuanwu Hospital, Capital Medical University, 100053 Beijing, China. Electronic address: yushun103@163.com.
authors.forename: Shun
authors.initials: S
authors.lastname: Yu
authors.affiliation: Center for Neurodegenerative Disease, Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, #6 Tian Tan Xi Li Street, 100050 Beijing, China. Electronic address: lifangfei401@sina.com.
authors.forename: Fangfei
authors.initials: F
authors.lastname: Li
authors.affiliation: Center for Neurodegenerative Disease, Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, #6 Tian Tan Xi Li Street, 100050 Beijing, China; Parkinson's Disease Center, Beijing institute for brain disorders, #10 You'an Men Wai Xi Tou Tiao, 100069 Beijing, China; China National Clinical Research Center for Neurological Diseases, #6 Tian Tan Xi Li Street, 100050 Beijing, China. Electronic address: happyft@sina.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Feng
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood*; D011108:Polymers; D051844:alpha-Synuclein / Q000097:blood* / Q000737:chemistry
chemical_list: D015415:Biomarkers; D011108:Polymers; D051844:alpha-Synuclein
keywords: Biomarker; Multiple system atrophy; Parkinson’s disease; Red blood cells; α-Syn oligomer