Levels of IL-8 and TNF-α decrease in Parkinson's disease

Peripheral immune system abnormalities are associated with Parkinson's disease, but role of inflammatory factors in Parkinson's disease has not been consistently proven yet. Thus, population-based studies are needed in the addition of peripheral dysfunction knowledge associated with Parkinson's disease. IL-8 and TNF-α are inflammatory factors that might be involved in PD. The aim of the present study was to evaluate the levels of IL-8 and TNF-α in Parkinson's disease patients from India.

Serum samples were collected from Parkinson's disease patients (n = 81) and their respective controls (n = 83). The levels of IL-8 and TNF-α were determined using Enzyme-linked immunosorbent assay.

The levels of IL-8 (patients = 222.70 ± 200.91 pg/ml, controls = 1584.44 ± 504.44 pg/ml; p < 0.001) and TNF-α (patients = 45.67 ± 24.69 pg/ml, controls = 638.25 ± 511.02 pg/ml; p < 0.001) were lower in the serum of Parkinson's disease patients than controls and the differences were statistically significant. Their levels were also significantly lower in both male and female patients as compared with their respective controls (p < 0.001). IL-8 was significantly lower in the female controls when compared with the male controls (p < 0.001). Their levels were not influenced by disease severity. Significant weak correlation was found between disease duration and the level of IL-8, but not with age at onset among patients. However, the level of TNF-α did not show correlation with disease duration and age at onset among patients.

The levels of IL-8 and TNF-α were significantly lower in serum of Parkinson's disease patients, which suggested that inflammatory factors might exert their effect and more specifically, inflammation might play crucial role in Parkinson's disease.