IMMUNOPHENOTYPIC CHARACTERIZATION OF IMMUNE CELL INFILTRATION SUBSETS IN MINOR SALIVARY GLANDS OF SJÖGREN SYNDROME

Abstract

Objective: The significance of distinct immune cell subsets in focal lymphocytic sialadenitis (FLS) of Sjögren syndrome (SS) remains to be established. The aim of this study was to assess the frequency of immune cells and their activation status in minor salivary glands (MSGs) from patients with SS. Study Design: Using immunohistochemistry, we examined the frequency and the activation status of FLS-infiltrating CD4+/CD8+ T cells, regulatory T cells (Tregs), CD56+ natural killer cells (NKs), dendritic cells (DCs), and plasma cells (PCs) in 18 MSGs biopsies from patients with SS. Results: CD4+ rather than CD8+ T cells/NKs were predominant, with scarce expression of granzyme B and perforin. CD138+ PCs were equally abundant and exhibited a higher amount of IgG+/Kappa+ cells. Tregs expressed higher levels of Foxp3 than CD25. DCs showed expression of both mature (CD83 and CD208) and immature (CD207, followed by CD1a) markers. Conclusion: Our results show a high proportion of CD4+, CD8+, and CD138+ cells, whereas Tregs, NKs, and DCs are scarce in MSGs from patients with SS. The CD25/Foxp3 proportion might indicate a distinctive Treg subset, supporting an abnormal immune cell modulation. Noteworthy, the early infiltration of monoclonal PCs emphasizes the probable lymphoma risk transformation in patients with SS. Objective: The significance of distinct immune cell subsets in focal lymphocytic sialadenitis (FLS) of Sjögren syndrome (SS) remains to be established. The aim of this study was to assess the frequency of immune cells and their activation status in minor salivary glands (MSGs) from patients with SS. Study Design: Using immunohistochemistry, we examined the frequency and the activation status of FLS-infiltrating CD4+/CD8+ T cells, regulatory T cells (Tregs), CD56+ natural killer cells (NKs), dendritic cells (DCs), and plasma cells (PCs) in 18 MSGs biopsies from patients with SS. Results: CD4+ rather than CD8+ T cells/NKs were predominant, with scarce expression of granzyme B and perforin. CD138+ PCs were equally abundant and exhibited a higher amount of IgG+/Kappa+ cells. Tregs expressed higher levels of Foxp3 than CD25. DCs showed expression of both mature (CD83 and CD208) and immature (CD207, followed by CD1a) markers. Conclusion: Our results show a high proportion of CD4+, CD8+, and CD138+ cells, whereas Tregs, NKs, and DCs are scarce in MSGs from patients with SS. The CD25/Foxp3 proportion might indicate a distinctive Treg subset, supporting an abnormal immune cell modulation. Noteworthy, the early infiltration of monoclonal PCs emphasizes the probable lymphoma risk transformation in patients with SS.