Study On The Characteristic Of B Cell Subsets In Autoimmune Hepatitis

ObjectiveAutoimmune Hepatitis（AIH）is a disease of abnormal liver function and corresponding clinical syndrome caused by over-activation of immune system.Traditionally,B cells are thought to participate in the pathogenesis of autoimmune diseases mainly through secretion of autoantibodies and presentation of autoantigen.Regulatory B cells（Bregs）are newly discovered groups of B lymphocytes that have a negative regulatory effect on the immune system.Their immunomodulatory effects are mainly through secretion of inhibitory cytokines such as interleukin-10（IL-10）.In this study,quantity and function of peripheral blood traditional B cells and Bregs were detected in newly diagnosed AIH patients and controls.MethodsThere were 30 AIH patients enrolled in this study,which receive the diagnosis between October 2016 and December 2017 from Gastroenterology Department at General Hospital of Tianjin Medical University.The negative controls consisted of 30 adult volunteers.peripheral blood mononuclear cells were collected from Peripheral blood,stimulated by LPS+Leukocyte Activation Cocktail（BD）for 5 hours.PB Bregs（CD19⁺IL-10⁺cells）、traditional B cells subsets(CD19⁺CD27^-CD38⁺⁺immature B cell、CD19⁺CD27^-CD38^-/+na?ve B cell、CD19⁺CD27⁺CD38^-/+memory B cell、CD19⁺CD27⁺CD38⁺⁺plasma cell)and Bregs subsets of AIH patient and controls were detected by flow cytometry,Secreted IL-10 were quantified in AIH patients and controls by ELISA.Results（1）The percentage of CD19+B cells in Lymphocyte of AIH patients was（7.29%±2.59%）and no statistical difference compared with negative controls （8.28%±2.13%,P=0.11）.The percentage of CD19⁺CD27^-CD38⁺⁺immature B cells in CD19⁺B of AIH patients was（6.78%±1.78%）and no statistical difference compared with negative controls（7.28%±1.25%,P=0.215）;The percentage of CD19⁺CD27⁺CD38⁺⁺plasma cells in CD19⁺B cells of AIH patients（4.43%±1.11%）was significantly higher than negative controls（1.75% ±0.64%,P<0.001）;The percentage of CD19⁺CD27⁺CD38^-/+Memory B cells in CD19⁺B cells of AIH patients（31.63%±6.76%）was significantly higher than negative controls（21.29%±5.19%,P<0.001）;The percentage of CD19⁺CD27^-CD38^-/+Na?ve B cells in CD19⁺B cells of AIH patients（57.16%±7.87%）was significantly lower than negative controls（69.18%±5.19%, P<0.001）;（2）The level of serum IL-10 of AIH patients was[（45.31±8.06）pg/ml]lower than that of the negative controls[（52.85±7.52）pg/ml,P=0.044].（3）The percentage of CD19+IL-10+cells in CD19+B cells of AIH patients（0.84%±0.28%）was significantly lower than negative controls（2.34%±0.62%,P <0.001）.The percentage of CD19⁺CD24^hiCD38^hii Bregs cells in CD19⁺B cells of AIH patients（3.17%±0.92%）was significantly lower than negative controls （5.93%±1.12%,P<0.001）;The percentage of CD19⁺CD24^hiCD27⁺Bregs cells in CD19⁺B cells of AIH patients（6.05%±1.21%） was significantly lower than negative controls（10.37%±1.25%,P<0.001）.ConclusionCompared with negative controls,the expression of B cell was no significantly different in peripheral blood of AIH patients,but the subsets of B cell were biased.Memory B cells and plasma cells were significantly increased,naive B cells were significantly decreased,the proportion of Bregs subsets was decreased,IL-10 secretion was decreased,suggesting that imbalance of B cell subsets may promote the incidence of AIH.Abnormal quantity and function of AIH patients,resulting in its failure to effectively inhibit the inflammatory response.The imbalance of the quantity and function of B cell subsets may be involved in the pathogenesis of AIH.