OBJECTIVE
To study the prevalence of chronic fatigue syndrome (CFS) and association of CFS with other clinical and neuropsychological manifestations of Parkinson’s disease (PD) as well as with serum inflammatory markers and genetic polymorphisms.
MATERIAL AND METHODS
The study included 533 patients with PD. All patients underwent clinical, neurological examination and neuropsychological testing using validated questionnaires: MoCA test, HADS, BDI-II, the Fatigue Severity Scale (FSS). Serum concentrations of inflammatory markers (slCAM-1, sVCAM-1, NCAM, CCL5, PAI-1 and MPO) were assessed in 144 patients using xMAP technology. A case-control study of CCL5 (rs2107538) and PAI-1 (rs2227631) gene polymorphisms was performed in connection with PD development and in groups differing in the presence/absence of CFS in PD. In addition, the relationship of these polymorphisms with variability in the levels of the corresponding proteins in the blood serum of patients was studied. Genotyping of CCL5 (rs2107538) and PAI-1 (rs2227631) polymorphisms was performed using real-time PCR with TaqMan probes.
RESULTS
CFS is common in 66.7% of patients in the PD group. In addition, non-motor symptoms (emotional-affective, cognitive, autonomic disorders and pain) were more common in patients with CFS. A strong correlation has been established between the severity of CFS assessed with FSS and serum concentrations of CCL5, sVCAM-1, NCAM and slCAM-1. In newly diagnosed patients with PD who were not taking antiparkinsonian drugs at the time of the study and had CFS, higher correlations were noted between inflammatory markers and the severity of CFS manifestations. When comparing the distribution of genotypes and alleles of CCL5 (rs2107538) and PAI-1 (rs2227631) polymorphisms, some differences were found between the groups of patients with PD and controls (p<0.05). However, these polymorphisms did not affect the variability of serum protein levels CCL5 and PAI-1, respectively, nor did they affect the development of CFS in patients with PD.
CONCLUSION
CFS is common in PD, and patients with PD and CFS are characterized by elevated levels of serum markers CCL5, sVCAM-1, slCAM-1 and NCAM, suggesting the importance of the inflammatory component in the development of neurodegenerative disease. In addition, the clinical course of PD in patients with CFS is aggravated by other non-motor manifestations, including emotional-affective, cognitive, autonomic disorders and pain. These results highlight the potential contribution of an inflammatory component to the development of fatigue associated with PD, starting from the earliest clinical stages of the disease.
