The expression and significance of T helper cell subsets and regulatory T cells CD₄⁺ CD₂₅⁺ in peripheral blood of patients with human leukocyte antigen B27-positive acute anterior uveitis.

Background: Human leukocyte antigen B27 (HLA-B27)-associated uveitis is the most common reason for non-infectious uveitis. This purpose of the research was to study the expression and significance of T lymphocyte subsets and CD₄⁺ CD₂₅⁺ T regulatory (Treg) cells in peripheral blood of patients with Human leukocyte antigen B27-positive acute anterior uveitis (HLA-B27-positive AAU).

Methods: The concentrations of Th1, Th2, Th17, CD₄⁺ CD₂₅⁺and CD₄⁺ CD₂₅⁺FOXP3⁺ Treg cells in peripheral blood were tested by flow cytometry. C-reactive protein (CRP) in peripheral blood was detected by immunoturbidimetry (ITM). Spearman's rank correlation was used to analyze the relationships between the concentration of Th1, Th2, Th17, CD₄⁺ CD₂₅⁺, and CD₄⁺ CD₂₅⁺ FOXP3(+) Treg cells in peripheral blood and disease activity score and CRP content.

Results: The ratio of both γ [interferon (IFN)-γ] (+)CD4⁺Th1 cells and CD4⁺IL-17⁺Th17 cells in peripheral blood of patients with HLA-B27-positive AAU (P = 0.041) was higher than that of the control group (P = 0.002). The concentration of CD₄⁺ CD₂₅⁺ FOXP3(+) T cells in peripheral blood of patients with AAU was lower than that of the control group (P = 0.026). The concentration of Th1 cells in peripheral blood of the patients had no correlation with disease activity score (P = 0.50) or CRP content (P = 0.383). This was also true of the concentration of Th2 cells (Disease activity score: R = 0.068, P = 0.817; CRP content: R = 0.439, P = 0.116). Th17 cell concentration positively correlated with disease activity score (R = 0.805, P = 0.001). The concentration of CD₄⁺ CD₂₅⁺ T cells showed no correlation with disease activity score (R =-0.209, P = 0.472) or CRP content (R =-0.169, P = 0.563), whereas the concentration of CD4⁺ CD25⁺ FOXP3⁺ T cells negatively correlated with disease activity score but did not correlate with CRP (R =-0.248, P = 0.392).

Conclusions: The peripheral blood of patients with HLA-B27-positive AAU showed a higher expression of interferon-γ and interleukin-17 cells in CD4⁺T cells, whereas CD4⁺CD25⁺FOXP3⁺ T cells displayed a lower expression of the cytokines. The balance between Th17 cells and CD4⁺  CD25⁺  FOXP3⁺ T cells may contribute to the activity of HLA-B27-positive AAU.