Sjogren's Syndrome Th17, Treg And In Patients With B-cell Research

Background. Primary Sjogren’s syndrome is an autoimmune disease with both organ-specific and systemic manifestations. pSS affects the salivary and lacrimal glands preferentially but may frequently also involve other exocrine glands. It is characterized by specific pathological features:the formation of ectopic lymphoid tissue. The mechanism of pSS is unclear and there is not any specific therapies either.Thl7and Treg are newly defined subgroups of helper T cell and are considered critical to the development of autoimmune diseases. B cell plays important role in the occurrence of pSS. However there is still fewer researches on the expression of Th17, Treg and memory B cell. B-lymphocyte activating factor (BAFF) is a key survival factor for B-cells and ensures their existence through reducing apoptotic clearance.Objective. To investigate the expression of CD4+IL-17+Th17cell, CD4+CD25+regulatory T cells (Tregs) and memory B cell, in the peripheral blood of patients with primary Sjogren’s syndrome (pSS) and healthy people. Then to examine BAFF level in pSS and in healthy controls. To analyze the correlations of the cells with clinical symptoms and lab tests.Methods. Samples of peripheral venous blood were collected from41newly diagnosed pSS patients from SICCA and PUMCH, all females and27healthy controls and7family members of the patients. The levels of CD4+IL-17+Th17cell, CD4+CD25+regulatory T cells (Tregs) and memory B cell in the peripheral blood were measured by flow-cytometric assay. The level of BAFF in serum is tested with ELISA. The clinical indexes including IgG, IgA, IgM, C3, C4, Focus score,5min salivary rate, ocular score, schirmer test were collected to analyze the correlations.Results. The level of CD4+IL-17+Th17in the blood of pSS patients was5.02%±1.95%, significantly higher than that of the healthy controls3.8%±1.0%(p=0.004). The level of CD4+CD25+Tregs in the blood of pSS patients was3.14%±1.63%, higher than that of the healthy controls2.8%±1.2%, but without statistical difference(p=0.098). The level of memory B cell in the blood of pSS patients was11.1%±5.1%, significantly higher than that of the healthy controls9.24%±6.99%(p=0.0002). There were no statistical differences between Th17, Treg, memory B cell in patients and in family members.(p>0.05). BAFF in pSS was1.18±0.72ng/ml, significantly higher than that of the healthy controls0.43±0.19ng/ml (p=0.0005) and also significantly higher than that of the family members0.56±0.11ng/ml (p=0.015). Th17level were significantly positively correlated with IgG(r=0.457,p=0.005). Treg level were significantly positively correlated with Focus score (r=0.480,p=0.005).CD27+B cell were significantly positively correlated with5min salivary rate (r=0.345,p=0.005) and significantly negatively correlated with ocular score (r=-0.321,p=0.041). BAFF was not correlated with IgG, IgA, IgM, C3, C4, Focus score,5min salivary rate, ocular score, schirmer test.(p>0.05)Conclusion. Th17is overexpressed in pSS patients and relationships than in healthy people. It is significantly positively correlated with IgG. Th17may involve in pSS mechanism. There is no statistic difference between pSS and controls. Its role in pSS is less obvious. Similarly the memory B cell is overexpression in pSS patients and relationships than in healthy people. It is negatively correlated with clinical indexes. It plays important roles in the developing of the disease. BAFF level is statistically elevated in pSS compared with relationships and controls. It is proved to be not associated with clinical disease activity in pSS. It is not parallel with exocrine dysfunction. These finding suggest that BAFF may contribute to pSS by other mechanisms.