Associations of serum neuromarkers with clinical features of Parkinson's disease

Abstract

To evaluate the clinical and laboratory correlation of biomarkers with anti- and pro-apoptotic activity with the severity of motor and non-motor symptoms depending on the progression rate of Parkinson's disease (PD). A wide range of non-motor symptoms (emotional-affective, cognitive, psychotic and behavioral disorders, fatigue, sleep disorders and autonomic disorders) was evaluated using validated scales and a number of serum neuromarkers responsible for neuroplasticity and neuronal survival processes (BDNF, PDGF, cathepsin D) in 71 patients with PD (mean age 65 (55; 70) years, disease duration 7 (4; 9) years, age of onset 57 (49; 62) years). The concentration of biomarkers (BDNF, PDGF and cathepsin D) was the lowest in the group of patients with a rapid PD progression rate (p<0.001, p=0.001 and p=0.031, respectively), the severity of motor and most non-motor symptoms was higher (p=0.023 and p=0.001, respectively) compared to middle and slow progression rate. There were correlations between BDNF concentration and the severity of depression (r=-0.63, p<0.001), apathy (r=-0.48, p<0.001), impulsive behavioral disorders (r=0.500, p<0.001), level of cognitive functions (r=0.54, p<0.001), motor symptoms (r=-0.43, p<0.001); between PDGF level and the severity of motor manifestations of PD (r=-0.30, p=0.011), depression (r=-0.70, p<0.001), apathy (r=-0.460, p<0.001), the degree of severity of behavioral disorders (r=0.742, p<0.001). No significant correlations were observed between the level of cathepsin D and the severity of clinical manifestations of PD, which indicates the connection of cathepsin D with the general pathogenesis of PD. The possibility of using serum proteins of the neurotrophin subfamily and the protein associated with autophagy, cathepsin D, as biomarkers that determine the prognosis of PD, is considered.