Increased frequency of CD4⁺CD25^high CD127^low regulatory T cells in patients with multiple sclerosis

Multiple sclerosis (MS), one of the most common diseases of the central nervous system (CNS), is characterized by demyelination and chronic inflammation of the CNS. Failure of immune tolerance and induced autoimmune processes are involved in MS immunopathogenesis. Regulatory T (Treg) cells play an important role in maintaining peripheral tolerance and immune homeostasis.

The aim of this study was to evaluate the frequency of CD4⁺CD25^highCD127^{low/ -}Treg cells in MS patients.

The study population was composed of 25 healthy controls (HCs), 35 patients with relapsing remitting multiple sclerosis (RRMS) and 25 patients with progressive multiple sclerosis (PMS). Frequency of CD4⁺CD25^highCD127^{low/ -} Treg cells in RRMS and PMS patients was compared with HC by flow cytometry.

Treg cells frequency in PMS patients was significantly higher compared to RRMS patients (P < 0.001) and HCs (P < 0.001). It was lower in RRMS patients than HCs (P = 0.005). A Significant direct correlation between Treg cells frequency and expanded disability status scale (EDSS) in PMS patients (P = 0.001, r = 0.6) was observed. Reverse correlation between Treg cells frequency and EDSS in RRMS patients was found (P = 0.01, r = -0.4).

More de-tailed clarification of the role of Treg cells in MS patients could provide a basis for development of Treg cells-mediated therapeutic strategies.