Expression of leptin in patients with primary Sjogren’s syndrome and its clinical significance

Background/Aims: Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by decreased salivary and lacrimal gland secretions. B-cell abnormalities have been identified in pSS. We tested the leptin (LP) and leptin receptor (LR) levels in pSS and to analyze relationship between their levels and clinical manifestation of pSS. Methods: We assayed LP and LPR levels measured by Flow Cytometry and the serum levels of LP and LR measured by ELISA in pSS patients compared with normal controls. Results: The expression of LPR in CD19+ B cell, serum levels of LP and LPR was significantly higher in pSS, higher in active pSS. The expression of serum BAFF was significantly higher in pSS. The expression of LP in CD19+ B cell was positively correlated with the serum sLPR, BAFF and LPR in CD19+ B cell. The expression of LPR in CD19+ B cell was positively correlated with the serum sLP and sLPR. The expression of LPR in CD19+ B cell in the group with oral ulcer was significantly lower than those without oral ulcer. The expression of serum LP in the group with dental caries was significantly lower than those without dental caries. The expression of serum LPR in the group with parotiditis was significantly higher than those without parotiditis. Conclusion: LP/LPR signaling may be a novel marker of disease. LP may play a role in the activation of B cells. LP/LPR may be involved in liver and renal damage and the pathogenesis of oral ulcer, dental caries and parotiditis in pSS.