Reduced Deltex1 Expression in T Cells Indicates Increased Disease Activity in Primary Sjögren’s Syndrome

Abstract

Abstract Background Deltex1 is a transcriptional target of NFAT that promotes T cell anergy. However, whether Deltex1 affects the properties of regulatory T cells (Tregs), which are involved in the pathogenesis of primary Sjögren’s syndrome (pSS), is unknown. Methods T cells were purified from peripheral blood using a negative selection method. Deltex1 mRNA levels were measured by quantitative reverse transcription polymerase chain reaction. The mean fluorescent intensity (MFI) of Tregs-associated molecules and the cytokine positivity of CD4 + FoxP3 + Tregs were analyzed using flow cytometry. The European League against Rheumatism Sjögren’s Syndrome Disease Activity Index (ESSDAI) and Patient- Reported Index (ESSPRI) were used to evaluate systemic disease activity and symptoms in pSS. Results Deltex1 expression in T cells was significantly lower in pSS patients than in age- and sex-matched healthy controls (p < 0.001). Deltex1 mRNA levels in T cells negatively correlated with visual analog scale scores for fatigue, ESSDAI, and ESSPRI (r = -0.334, p = 0.035; r = -0.364, p = 0.021; and r = -0.340, p = 0.032, respectively). Low Deltex1 levels correlated with some clinical manifestations of pSS, including immune thrombocytopenia, vasculitis, and autoimmune thyroiditis (p = 0.014, 0.002, and 0.001, respectively). The MFI of PD-1, CTLA-4, TIM-3, LAG-3 on Tregs and the percentage of interferon-γ +, interleukin (IL)-4+, IL-17A + Tregs were significantly higher in the low Deltex1 group (Deltex1/GAPDH ≤ 0.02) than in the high Deltex1 group (Deltex1/GAPDH > 0.02) (p < 0.05). Conclusion Deltex1 may affect the properties of Tregs; thus, it is a potential biomarker of disease activity in pSS.