October 23, 2017Neurology
Parkinson's disease (PD) is a neurodegenerative disorder in which dopamine-producing brain cells die off, resulting in tremors, muscle stiffness, loss of balance and slow movement. Additional symptoms may include emotional changes and disrupted sleep. According to an article published online in Nature (June 21, 2017A), a new study suggests that T cells, which help the body's immune system recognize friend from foe, may play an important role in PD.
For the study, the authors collected blood samples from 67 individuals with PD and 36 healthy controls. Immune cells were extracted from the samples and mixed with portions of the alpha-synuclein protein, which accumulates in the brains of people with PD and can result in cell death. Results that T cells from people with PD responded to the presence of alpha-synuclein to a much greater degree than those gathered from the control group. In particular, two regions of alpha-synuclein evoked reactions from T cells: a section that often contains mutations linked with PD, and a portion undergoing a chemical change that can lead to accumulation of the protein in the brain. The authors identified four genetic variations that were associated with T cell reactivity to alpha-synuclein. More than half of people with PD carried at least one of those variants, compared to 20% of controls.
According to the authors, these findings expose a potential biomarker for PD that may someday help in diagnosing the disease or be used to evaluate how well treatments are working. The authors added that the results also suggest that PD may have characteristics of an autoimmune disease, in which the immune system incorrectly attacks the body's own cells.