The brain-derived neurotrophic factor (BDNF) is a potent inhibitor of apoptosis-mediated cell death and neurotoxin-induced degeneration of dopaminergic neurons. There is a growing body of evidence implicating BDNF in the pathogenesis of Parkinson's disease (PD), suggesting it may eventually be used in the development of neuroprotective therapies for PD. The serum BDNF of 47 PD patients and of 23 control subjects was assessed, and serum BNDF levels were significantly decreased in PD patients when compared with controls (p = 0.046). Interestingly enough, BDNF correlated positively with a longer time span of the disease, as well as with the severity of the PD symptoms and with more advanced stages of the disease. Additionally, higher BDNF levels also correlated with poor balance as assessed by the Berg Balance Scale, more time spent at the Timed Up & Go Test, reduced speed of gait and shorter distance walked during the Six-Minute Walk Test. Our results corroborate the literature regarding the involvement of BDNF in PD. We hypothesize that lower BDNF levels in early stages of the disease may be associated with pathogenic mechanisms of PD. The increase of BDNF levels with the progression of the disease may be a compensatory mechanism in more advanced stages of PD.

Some studies have demonstrated altered circulating levels of cytokines, including IL-6, in Parkinson's disease (PD), implying a possible involvement of inflammatory and immune-mediated mechanisms in its pathogenesis. Moreover, the increased production of inflammatory cytokines has been associated with cognitive impairment and poor physical performance in the elderly. We compared serum levels of IL-6 in 44 PD patients and 22 healthy subjects, and correlated them with PD specific instruments and functional tests. Serum levels of IL-6 were significantly increased in PD (p=0.015). There was no correlation between serum levels of IL-6 and instruments traditionally used to assess PD severity. However, we found that PD patients with higher serum levels of IL-6 spent more time at functional mobility tests and had lower gait speed. Also, these patients had major problems to keep balance during functional tasks that required postural changes and that had a reduced base support. These results showed that high levels of IL-6 can be involved with an acceleration of muscle catabolism leading to sarcopenia, therefore contributing to weakness and fatigue, and may also be associated with functional disability in PD.

No abstract

Brain-derived neurotrophic factor (BDNF) is the most widely distributed neurotrophin in the CNS, where it plays several pivotal roles in synaptic plasticity and neuronal survival. As a consequence, BDNF has become a key target in the physiopathology of several neurological and psychiatric diseases. Recent studies have consistently reported altered levels of BDNF in the circulation (i.e., serum or plasma) of patients with major depression, bipolar disorder, Alzheimer's disease, Huntington's disease and Parkinson's disease. Correlations between serum BDNF levels and affective, cognitive and motor symptoms have also been described. BDNF appears to be an unspecific biomarker of neuropsychiatric disorders characterized by neurodegenerative changes.

Although patients and controls exhibited similar scores of resilience, CKD negatively impacted the QoL of pediatric patients, contributing to a higher frequency of depression and separation anxiety.