Abstract: Objective To investigate whether α-synuclein levels in peripheral erythrocytes are associated with early-onset Parkinson‘s disease(PD). Methods The subjects included 47 patients with early-onset PD and 52 healthy controls.The venous blood was obtained to separate erythrocyte.  The electrochemiluminescence assay was used to measure total and oligomeric α-synuclein levels. After 2 year  25 PD patients were re-examined with repeated blood collection and clinical assessments. Results Compared with control group total and oligomeric α-synuclein levels in erythrocyte  in early-onset PD groups were significantly increased［total α-synuclein: 1.28(0.94, 2.13) vs  0.57(0.41, 0.70), P<0.001; oligomer: 202.18(152.16, 244.22) vs 128.40(107.61, 157.02), P<0.001］. In the follow-up study over 2 years, motor and cognitive scores did not process after 2-year follow-up,   but erythrocytic oligomeric α-synuclein levels in early-onset PD  were significantly increased than that at baseline ［211.66(159.71, 263.73) vs 170.12(139.31, 233.42), P=0.046］. Conclusion Our study suggests that total and oligomeric α-synuclein in erythrocyte were elevated in early-onset PD and could serve as a potential diagnostic biomarker for PD and could serve as a potential diagnostic biomarker for PD.

Key words: early-onset Parkinson’s disease, erythrocyte, α-synuclein, biomarker