Authors: Raymond Chong, Chandramohan Wakade, and Eric Bradley
Neuroinflammation plays a crucial role in the pathogenesis of Parkinson’s disease (PD)1,2. Systemic inflammation is known to contribute to the ongoing neurodegeneration in PD and is also a sequel to PD symptoms in early and late stages (1). Pro and anti-inflammatory cytokines levels may associate with the severity of the PD symptoms2. Sleep quality has also been associated with inflammation. We examined the plasma levels of thirteen cytokines in PD patients, age-matched controls, and young healthy controls: GM-CSF, IFN-γ, IL-10, IL-12, IL-13, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, and TNF-α. Milliplex MAP Human Cytokine Assay kit was utilized to measure these using human cytokine magnetic beads at 0.08 - 1.01 pg/mL sensitivity. Moderate PD patients demonstrated significantly higher levels of IL-4 compared to all elderly controls (p=0.016). IL-6 was higher in moderate PD patients compared to young healthy controls (p=0.026). Levels of IL-7 were higher in moderate PD patients (p=0.002), both mild and moderate PD patients (p=0.007) and all elderly controls (p=0.006) compared to young healthy controls. Similarly, all the PD patients demonstrated higher levels of IL-8 (p=0.047) and TNF-α (p=0.025) compared to all young healthy controls. In conclusion, cytokine levels in PD, particularly IL-7 need to be further explored using larger samples.
Keywords: quality of life, sleep efficiency, inflammation