Effects of peripheral lymphocyte subpopulations and the clinical correlation with Parkinson's disease

Aim: To understand the characteristics of peripheral immunity in patients with Parkinson's disease (PD), we investigated the natural killer (NK) cell activity and lymphocyte subpopulations including regulatory T (Treg) cells and type 17 helper T (Th17) cells. Methods: Peripheral blood was collected from 29 PD patients (mean age 70.4 years) and 30 healthy controls (mean age 68.9 years). NK cell activity was measured by a calcein acetoxymethyl ester release assay using NK-sensitive K562 cells, peripheral NK cells and lymphocytes subsets were analyzed using flow cytometry techniques. Results: Comparison of the two groups demonstrated that the percentage of NK cells increased and that of helper T cells, particularly type 1 (Th1), decreased in patients with PD. There was no evidence of Th1/Th2 or Treg/Th17 cell predominance in PD. Moreover, the increase of NK cells and the decrease of Th1 cells correlated with Unified Parkinson's Disease Rating Scale scores and the heart-to-mediastinum ratios based on myocardial 123I-metaiodobenzylguanidine uptake, both of which represent disease severity in patients with PD. Conclusion: Our investigation indicates that a certain proportion of NK cells and other lymphocytes in the peripheral blood of patients with PD and their association with disease severity may reflect the effect of innate immunity in patients with PD in addition to the effect of dopaminergic-related agents. Geriatr Gerontol Int 2012; 12: 102-107.