Purpose: Primary Sjögren's syndrome (pSS) has been proven as a systemic autoimmune disorder (such as Sjogren's syndrome dry eye). This research aimed to evaluate potential treating effects of Iguratimod on pSS.
Methods: Fifty pSS patients were enrolled and randomly divided into Conventional group and Iguratimod group. Improvement in pSS was evaluated every 4 weeks. pSS disease activity was evaluated with European League Against Rheumatism (EULAR) Sjögren's syndrome disease activity index (ESSDAI). Symptoms were evaluated by determining EULAR Sjögren's syndrome patient-reported index (ESSPRI), platelet (PLT), IgG and Schirmer I test. Peripheral blood B cell molecules (CD135, IgD, CD38, CD20) and human B cell-activating factor-receptor (BAFF-R) were analyzed with flow cytometry.
Results: After treating for 12-weeks, pSS patients in Iguratimod and Conventional group showed a significant decrease in disease activity (ESSPRI, ESSDAI, PLT, IgG and Schirmer I test) comparing with baselines. Patients' ESSPRI (2.92 ± 0.19) and disease activity of ESSDAI (4.32 ± 0.29), PLT (95.64 ± 1.86), IgG (13.0 ± 0.45) and Schirmer I test (4.67 ± 0.31) in Iguratimod group were significantly lower compared to Conventional group (4.64 ± 0.15, 5.8 ± 2.08, 77.44 ± 1.41, 16.5 ± 0.44 and 2.25 ± 0.11) (p < 0.0001). Changes of ESSPRI, ESSDAI, PLT, IgG and Schirmer I test were remarkable observed between two groups (p < 0.001). Iguratimod and Conventional treatment demonstrated a significant reduction in total B cells in pSS patients compared with pre-treatment. The pSS patients from Iguratimod and Conventional group showed a significant decreased BAFF-R (61.82 ± 1.52, 74.07 ± 1.11) and CD38+IgD+ (48.08 ± 0.92, 62.66 ± 1.12) on B cells after treatment compared with baseline (92.26 ± 0.32, 91.53 ± 0.45, 84.39 ± 0.59, 85.04 ± 0.46) (p < 0.001). After treating 12 weeks, BAFF-R, CD38+IgD+ expression in Iguratimod group decreased significantly compared to Conventional group (p < 0.001).
Conclusions: Iguratimod alleviated symptoms and mediated adaptive-immunity balance by suppressing BAFF-R positive B cell in pSS patients.
Keywords: Arthritis; B cell; Iguratimod; Primary Sjögren’s syndrome.