Objective: The aim of our present study is to investigate the role of plasmacytoid dendritic cells (pDCs) in the pathogenesis and type I interferon (IFN) signatures in Primary Sjögren’s Syndrome (pSS) patients. Methods: In the present study, we compared the percentage, activation markers, and representative cytokines secretion of pDCs derived from treatment-naive pSS and matched healthy controls (HCs) by flow cytometry. We performed pDC/B co-culture system to explore the contribution of pDC to B cell functions in pSS. Results: The percentage of pDC was significantly reduced in the peripheral blood of pSS. The activation markers (CD80, CD83, and CD86) expressions, chemokine receptors, and representative cytokines production (IFN-α, IL-6, and TNF-α) of pDC were similar between pSS and HCs. Only a few pDCs infiltration were detected in the labial gland. The percentage of pDCs was negatively correlated with serum IgG, IgA, and anti-SSA autoantibody levels and resting pDCs were able to efficiently promote B cells proliferation, activation, differentiation, and antibody production in vitro. However, there was no difference between HC and pSS-derived pDCs. Finally, we found that incubation of plasma from pSS patients could significantly induce pDCs apoptosis than that from HCs and both IgG and IgA dramatically increased the apoptotic rates of pDCs. Conclusion: Our data have deciphered the redundant role of pDC in the type I signature and disease development in pSS. Also, we demonstrated the decreased percentage of pDC in pSS patients might result from apoptosis induced by the excess of immunoglobulin (IgG and IgA).

Objective： Although specific anti-phospholipids antibodies (aPLs) have been used in the diagnosis of the antiphospholipid syndrome (APS) for years, new biomarkers are required to increase its diagnostic as well as risk-predictive power. This study aimed to explore the value of several extra-criteria aPLs in a Chinese cohort. Methods： A total of 312 patients including 100 patients diagnosed with primary APS, 51 with APS secondary to SLE, 71 with SLE, and 90 health controls were recruited. Serum anticardiolipin (aCL) IgG/IgM/IgA, anti-β2-glycoprotein I (aβ2GPI) IgG/IgM/IgA, anti-phosphatidylserine/prothrombin antibodies (aPS/PT) IgG/IgM, anti-annexin A5 antibodies (aAnxV) IgG/IgM were tested using ELISA kits. Results： Totally 30.46% and 6.62% of patients with APS were positive for aCL or aβ2GPI IgA respectively, while 39.07% and 24.50% were positive for aAnxV or aPS/PT for at least one antibodies (IgG or IgM). The addition test of aCL IgA and aAnxV IgM assist in identifying seronegative APS patients, and IgG aANxV was linked with stroke. Conclusion： Detection of aCL IgA, aβ2GPI IgA, aAnxV IgG/M, and aPS/PT IgG/M as biomarker provide additive value in APS diagnosis, and would help in risk prediction for APS patients in medical practice.