Objective: Sjögren's syndrome (SS) is an inflammatory autoimmune disease. We investigated important factors associated with the expression of inflammation-related molecules in minor salivary gland (MSG) mononuclear cells in patients with SS.
Methods: Thirty-four patients with SS with a MSG biopsy grading of either grade III (10 patients) or grade IV (24 patients) were enrolled. The age, sex, autoantibodies, cell infiltration, and intercellular adhesion molecule-1 (ICAM-1), matrix metalloproteinase-3 (MMP-3), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), or CXCR3 expression were also analyzed.
Results: Ten of the 34 patients with SS were diagnosed with secondary SS; in these patients, the diagnosis of rheumatoid arthritis was confirmed in 8 and systemic lupus erythematosus in 2. TRAIL and ICAM-1 were overexpressed in patients with antinuclear antibodies (ANA) > 1:160, compared to those with titer < 1:160 (45.1 +/- 4.4 vs 41.2 +/- 3.9, p = 0.021, and 15.2 +/- 5.7 vs 10.8 +/- 3.3, p = 0.018, respectively). Higher erythrocyte sedimentation rate (ESR; >OR= 20) was associated with higher TRAIL expression and CD20 cell infiltration in contrast to lower ESR (< 20; p < 0.05). ICAM-1, TRAIL, and MMP-3 were expressed more predominantly in anti-SSA-positive than in anti-SSA-negative patients with SS. There was a significant difference in CD20 cell infiltration and MMP-3 expression between primary SS and secondary SS. Biopsy of a grade IV showed a significantly increased expression of TRAIL (44.9 +/- 4.5 vs 40.8 +/- 3.6, p = 0.013) and MMP-3 (62.7 +/- 6.3 vs 54.4 +/- 7.3, p = 0.003) in mononuclear cells as compared to those of grade III.
Conclusion: In our study, pathologic grading with a higher grade (grade IV) and the presence of SSA or a higher titer of ANA were significantly associated with the overexpression of TRAIL, MMP-3, or ICAM-1 in the salivary gland mononuclear cells in patients with SS.