Diagnostic values of serum levels of α-synuclein, homocysteine and leucine-rich α2 glycoprotein for predicting cognitive impairment in Parkinson's disease.

Abstract

Background: α-synuclein, homocysteine (Hcy) and leucine-rich α2-glycoprotein (LRG) have been shown to correlate to Parkinson's disease (PD). However, it remains unclear whether these factors are associated with the occurrence of cognitive impairment (CI) in PD patients.

Methods: This study initially enrolled eligible PD patients without cognitive impairment. Blood samples were collected to measure serum levels of α-synuclein, Hcy, and LRG using enzyme-linked immunosorbent assay. After one year of treatment, patients were divided into CI group and non-CI groups based on their Montreal Cognitive Assessment (MoCA) scores. Baseline clinical characteristics and the levels of these three factors were compared between the two groups. Additionally, Receiver Operating Characteristic (ROC) analysis was used to assess the predictive value of these factors for the occurrence of CI in PD patients.

Results: The study included 102 eligible PD patients without baseline CI, divided into 65 patients in the non-CI group and 37 patients in the CI group after one year, based on the MoCA scores. Serum levels of α-synuclein, Hcy, and LRG in the CI group were 0.42 ± 0.33 ng/mL, 19.85 ± 6.31 µmol/L, and 14.53 ± 5.11 ng/mL respectively, compared to 0.04 ± 0.03 ng/mL, 14.32 ± 5.25 µmol/L, and 11.67 ± 3.10 ng/mL in the non-CI group. Patients in the CI group had MoCA scores below 26, indicating cognitive impairment. ROC analysis revealed that α-synuclein, Hcy, and LRG levels effectively predicted the occurrence of CI in PD patients.

Conclusions: Serum levels of α-synuclein, Hcy and LRG were elevated in the CI group compared to the non-CI group, suggesting that these factors may serve as predictors of cognitive impairment in PD patients.