Abstract

Objectives: Parkinson disease (PD), a neurodegenerative disease, has also some immunologic basis in which several regulatory factors, like Helios and Neuropilin-1 (NRP-1) may show some roles in its pathogenesis. We aimed to evaluate the circulatory frequency of T regulatory cells (Tregs) expressing Helios and NRP-1 in PD. Patients and Methods: In this case-control study, 83 patients with PD and 83 healthy controls were enrolled. The diagnosis of PD was accomplished in accordance with clinical diagnostic criteria of the UK Parkinson Disease Society Brain Bank. The modified Hoehn and Yahr (H and Y) were used to measure the severity of PD. Flow cytometry was used to evaluate the circulatory frequency of CD4+CD25+Foxp3+Tregs expressing and Helios and NRP-1 in all participants. Also, correlation of H and Y with such frequencies was evaluated. Results: Our findings showed that frequency of CD4+CD25+Foxp3+Tregs expressing NRP-1 (P= 0.04) and Helios (P= 0.01) in patients with PD was significantly higher than those in healthy subjects. The frequency of Tregs expressing Helios and NRP-1 showed a negative correlation with H and Y criteria and disease duration. Multiple linear regression analysis indicated that the severity of PD is the only effective factor on the frequency of CD4+CD25+Foxp3+NRP-1+Tregs (P= 0.012) and CD4+CD25+FoxP3+ Helios+ Tregs (P= 0.038). Conclusion: Our study showed that the increased frequency of Tregs expressing Helios and NRP-1 is associated with the severity of PD.