Increased serum levels of soluble tumor necrosis factor-α receptor-1 in patients with Parkinson's disease

Parkinson's disease (PD) is characterized by a progressive and irreversible loss of dopaminergic neurons. Inflammatory mechanisms have been implied in the pathophysiology of PD. In this study, we assessed serum levels of TNF-α and the soluble forms of their receptors, sTNFR1 and sTNFR2, in 46 PD patients and 23 control subjects. Patients with PD had higher levels of sTNFR1 (p = 0.048). The concentration of sTNFR1 and sTNFR2 correlated with age (p = 0.006 and p = 0.022, respectively). Higher levels of sTNFR1 were associated with later disease onset (p = 0.048). These results corroborate the role of inflammatory events in the process of neurodegeneration in PD which can be of special relevance in the sporadic form of PD with later onset.