Immunophenotypic Profiling Reveals Circulating Lymphocyte Dysregulation in Primary Sjögren's Syndrome

Area of Science:

• Immunology
• Rheumatology

Background:

• Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease characterized by lymphocytic infiltration of exocrine glands.
• Immune system dysregulation, particularly involving T and B lymphocytes, is implicated in pSS pathogenesis.

Purpose of the Study:

• To identify specific peripheral T and B cell subset alterations in patients with primary Sjögren's syndrome.
• To investigate the association between these immune cell subset changes and the disease activity, as measured by the European Sjögren's Syndrome Disease Activity Index (ESSDAI).

Main Methods:

• Flow cytometry analysis of peripheral blood mononuclear cells from 43 pSS patients and 46 healthy controls.
• Collection of demographic data and clinical manifestations for all participants.

Main Results:

• pSS patients showed increased frequencies of naïve CD4+ T cells, central memory CD4+ T cells, virus-specific CD8+ T cells, Th2/Th17 cells, total B cells, and CD21-/low B cells.
• Reduced levels of terminally differentiated/exhausted CD4+ T cells, Th1/Tc1 cells, and plasma cells were observed in pSS patients.
• Disease activity (ESSDAI) positively correlated with Tc cells and CD21-/low B cells, and inversely correlated with plasma cells.

Conclusions:

• Peripheral T and B cell subset dysregulation is a key feature of primary Sjögren's syndrome.
• Specific immune cell subsets are associated with disease severity in pSS, suggesting their role in immune dysfunction and disease progression.