Relationship between the plasma levels of neurodegenerative proteins and motor subtypes of Parkinson’s disease

Abstract

The aim of our study is to examine the plasma levels of the four kinds of neurodegenerative proteins in plasma: α-syn, T-tau, P-tau and Aβ-42 in Parkinson's disease (PD) and to evaluate the relationship between their plasma levels and PD motor subtypes. 84 patients with PD were enrolled in our study, and finally, 73 of them were classified into the tremor-dominant subtype (TD) and the postural instability gait difficulty subtype (PIGD). Their motor performance was evaluated by a series of clinical assessments: Freezing of Gait Questionnaire (FOGQ), Timed Up and Go (TUGs), Tinetti balance, and Tinetti gait. Plasma levels of these proteins were measured by enzyme-linked immunosorbent assay (ELISA). The plasma level of α-syn was significantly higher in PD patients when compared to controls (p = 0.004), and significantly higher in the PIGD group when compared to the TD group (p = 0.03). While the plasma level of Aβ-42 was significantly lower in PD patients than in controls (p = 0.002), and significantly lower in the PIGD group than in the TD group (p = 0.05). In PD patients, the plasma level of α-syn (r = -0.355, p < 0.001) was significantly related to the severity of Tenitti Gait score, even after performing multiple linear regression (p = 0.002). While the plasma level of Aβ-42 (r = -0.261, p < 0.05) was significantly associated with the severity of PIGD score and remained correlate when performed multiple linear regression (p = 0.005). The patients with PIGD subtype are characterized with a lower level of plasma Aβ-42 and a higher plasma level of α-syn, which may be used as biomarkers for diagnosis and progression of the subtypes of PD.

Utility of plasma Neurofilament light as a diagnostic and prognostic biomarker of the postural instability gait disorder motor subtype in early Parkinson’s disease

“…Fewer studies, however, have attempted to identify blood-based biomarkers that can similarly discriminate between PD motor subtypes, a significant gap given the less invasive nature of blood sampling vs CSF sampling. Patients with the PIGD subtype were reported to have lower plasma Aβ-42 and higher plasma α -synuclein levels than the TD group [28], while our group has previously reported higher serum uric acid levels in the TD motor subtype [29].…”

Plasma and Serum Alpha-Synuclein as a Biomarker of Diagnosis in Patients With Parkinson's Disease

“…Depending on pathogenesis, many published studies focused on α-synuclein, which is a major constituent of Lewy bodies (4). The majority of researches on levels of different subtype α-synuclein including total (5)(6)(7), oligomeric (8,9), and phosphorylated (9,10) form in body fluids have been conducted for the cerebrospinal fluid (CSF) (8)(9)(10)(11)(12)(13)(14); however, only a few studies have investigated α-synuclein levels in peripheral blood (5-7, 15, 16), and two studies have been done in serum (16,17). The results of those body fluids between patients with PD and normal control has been controversial (18,19); additionally, the correlation between the severity of motor symptoms and the levels of α-synuclein in CSF or peripheral blood is still under investigation (7,9).…”

Serum soluble lymphocyte activation gene‐3 as a diagnostic biomarker in Parkinson's disease: A pilot multicenter study

“…[1][2][3][4][5] However, the results of these studies were inconsistent with previous studies. 6,7 Therefore, the identification of novel and reliable biomarkers would be important in the development of future novel therapies and diagnostics for PD.…”