CD4 and Parkinson disease: To further determine the relevant clinical features of CD8+ Tn cells and LD CD4+ T cells, we used multiple regression models to explore the association between their proportions and characteristics of PD patients (age of disease onset, course of the disease, LEDD, H&Y, scores of motor symptoms scales included MDS-UPDRS, BBS, Mini-BEST, SPES/SCOPA, scores of non-motor symptoms included NMSS, HRS, CSI, PSQI, RBDSQ, ESS, RLS, HAD, HAMD-17, MMSE, SCOPA-AUT, SCOPA-PC, and scores of life quality from PDQ-39).