The proportion and phenotypic changes of CD4CD25Foxp3 T cells in patients with untreated rheumatoid arthritis.

Objective: CD4CD25Foxp3 regulatory T (Treg) cell-mediated immunosuppression is an essential mechanism of rheumatoid arthritis (RA). However, little is known regarding the specific role of CD4CD25Foxp3 Treg cells in RA. This study aimed to investigate the frequency of circulating CD4CD25Foxp3 Treg cells and their role in RA.

Methods: Sixty-one untreated RA patients and 40 healthy controls (HCs) were enrolled in this study. The proportion of CD4CD25Foxp3 T cells and CD4CD25Foxp3 Tregs; the levels of CTLA4, GITR, Helios, and ICOS; and the production of IL-17A, IFN-γ, and IL-10 were assessed by flow cytometry. The correlation of CD4CD25Foxp3 T cells and CD4CD25Foxp3 Tregs with the clinical indicators was conducted by Spearman correlation analysis.

Results: The proportion of CD4CD25Foxp3 T cells was elevated in RA and positively correlated with disease activity. CD4CD25Foxp3 T cells expressed less Helios and produced more IFN-γ than conventional Tregs in RA. Additionally, the proportion of CD4CD25Foxp3 T cells was positively correlated with DAS28 score, IgG titer, and anti-CCP titer.

Conclusions: These data indicate that CD4CD25Foxp3 T cells in RA exhibit several different functional properties from conventional Tregs and are correlated with RA disease activity.