Session Information
Date: Sunday, October 26, 2025
Title: (0506–0521) Sjögren’s Disease – Basic & Clinical Science Poster I: Etiology, Pathogenesis, Diagnosis
Session Type: Poster Session A
Session Time: 10:30AM-12:30PM
Background/Purpose: Primary Sjögren’s Syndrome (pSS) is an autoimmune disease characterized by lymphocytic infiltration of exocrine glands and systemic manifestations including cutaneous and renal involvement. Phagocytes–monocytes, neutrophils, and dendritic cells– are innate immune cells playing crucial roles in both innate defence and modulation of adaptive immunity. Dysregulation of these cells in pSS has been linked to altered inflammatory response, although the mechanisms driving disease progression remain unclear. PSGL-1 is a leukocyte adhesion molecule and a checkpoint for the immune system. High expression level of HLA-DR is a sign of immune activation. Additionally, higher production of IFNα has been related to pSS pathogenesis
Methods: We obtained the peripheral blood of 44 pSS patients and 26 healthy donors (HD). The percentage of cells expressing PSGL-1, HLA-DR and IFNα mean fluorescence intensity (MFI) was analysed by flow cytometry in neutrophils, monocytes (both classical and non-classical), and plasmacytoid dendritic cells (pDC). Statistical differences between HD and patients were calculated using Mann-Whitney U test or Student’s T-test. Association of the different variables with the presence of the disease was assessed by binary logistic regression (BLR). Then, we performed its receiver operating characteristic (ROC) curves. Statistical significance was set at p< 0.05. Statistical analyses were performed using SPSS 25.0 and GraphPad Prism 8 software.
Results: Compared to HD, the percentage of HLA-DR-expressing cells was increased in neutrophils, monocytes, and pDC of pSS patients. The expression level was higher in pDC and monocytes, suggesting constitutive immune activation in pSS patients. The percentage of neutrophils and pDCs expressing PSGL-1 and PSGL-1’s MFI of non-classical monocytes were reduced compared to HD. This reduction may contribute to higher leukocyte activation. However, the expression level of PSGL-1 in non-classical monocytes was increased. Regarding IFN-α, we found an elevated percentage of neutrophils, classical monocytes and pDC producing IFNα in pSS patients and reduced percentage of non-classical monocytes. BLR analyses identified percentage of neutrophils expressing HLA-DR (79.6% sensitivity, 56.7% specificity and AUC 0.756), percentage of pDC expressing IFNα (92.7% sensitivity, 13.6% specificity and AUC 0.634) and ratio of conventional dendritic cells (cDC) and pDC (83.7% sensitivity, 60% specificity and AUC 0.75) as potential biomarkers for pSS diagnosis.
Conclusion: Our findings underscore an important role of phagocytes in maintaining chronic immune activation in pSS patients. The altered expression of these molecules in innate cell populations might contribute to disease’s pathogenesis. The results contribute to our understanding of phagocyte involvement in pSS and offer potential new avenues for diagnostic strategies.
To cite this abstract in AMA style:
Castañeda S, Ramos-Manzano A, Sanchez-Abad I, Uriarte-Ecenarro M, Alvarez-Hernandez M, San-Antonio E, Vicente-Rabaneda E, Urzainqui A. Deregulation of PSGL-1, HLA-DR and IFNα expression in peripheral innate immune cells of primary Sjögren Syndrome patients [abstract]. Arthritis Rheumatol. 2025; 77 (suppl 9). https://acrabstracts.org/abstract/deregulation-of-psgl-1-hla-dr-and-ifn%ce%b1-expression-in-peripheral-innate-immune-cells-of-primary-sjogren-syndrome-patients/. Accessed .« Back to ACR Convergence 2025
ACR Meeting Abstracts - https://acrabstracts.org/abstract/deregulation-of-psgl-1-hla-dr-and-ifn%ce%b1-expression-in-peripheral-innate-immune-cells-of-primary-sjogren-syndrome-patients/