The Clinical Significance Of Bregs,IL-10 And TGF-β1 In The Serum Of Children With Myasthenia Gravis

Aim:Myasthenia gravis(MG)is a kind of autoimmune disease which is mediated by AchR-Ab receptor(AchR-Ab).MG mainly involving the NMJ postsynaptic membrane acetylcholine receptor(acetylcholinergic receptor,AChR)can lead to the the transfer of obstacles at neuromuscular junction(NMJ).Cytokines,complement and some lymphocytes participate in this process.B cells and the AchR-Ab they produced are the main mechanisms of myasthenia gravis(MG).Regulatory B cells(Bregs)are a group of B lymphocytes with immunosuppressive function.They regulate immune responses by secreting cytokines such as IL-10 and TGF-β1 and play an important role in the maintenance of peripheral immune tolerance.The missing of their function can lead to the disorder of the balance of autoimmune and cause autoimmune diseases.It had been reported that Bregs by producing IL-10 and TGF-β1 could inhibit autoimmune arthritis mediated by Th17 cells and inhibit the proliferation and differentiation of Th17.Furthermore,by the secretion of IL-10,Bregs could also inhibit the progress of the disease and reduce the severity of the disease.But whether Bregs and IL-10 and TGF-β1 they secreted participated in the occurrence and progress of MG had been few elucidated until now.In this study,flow cytometry was used to detect the difference of CD19+CD5+CD1d+Breg cells in serum from MG patients and outpatients and the difference of CD19+CD5+CD1d+Breg cells in MG patients in different clinical stages.ELISA method was used to detect serum expression of IL-10 and TGF-β1 in MG patients and outpatients and difference in the expression level in MG patients in different clinical stages.In order to further understand the pathogenesis of MG and to provide theoretical and experimental basis for further clinical diagnosis and treatment.Methods:Serum from 56 cases with MG:25 males and 31 females with a mean age of 4.9±2.2 years were collected from Children’s Hospital of Henan Province from January2014 to January 2017.Serum from 26 outpatient cases:10 males and 16 females with an average age of 4.1±2.1 years were also collected from Children’s Hospital of Henan Province from January 2014 to January 2017 meanwhile.The number of CD19~+CD5~+CD1d~+Breg cells and the expression of IL-10 and TGF-β1 in serum samples were determined by flow cytometry and ELISA.Results:1.The results of Flow cytometry demonstreted that the number of CD19~+CD5~+CD1d~+Breg cells in serum of children with MG(2.78±0.02%)was significantly decreased compared with those in control group(5.73±0.03%).2.The results of Flow cytometry also showed that there had a significant difference in the number of Bregs in serum of children with MG in different clinical stages.The number of Bregs in stageⅠwas 2.97±0.21%,in stageⅡ2.77±0.16%,in stageⅢ2.54±0.13%,in stageⅣ2.13±0.11%and in stageⅤ1.92±0.08%.The number of Bregs cells decreased with the progression of the disease.3.The serum levels of IL-10(0.19±0.02 pg/ml)and TGF-β1(0.55±0.08 pg/ml)in children with MG measured by ELISA were decreased greatly compared with the levels of IL-10 in the serum of the control group(0.51±0.08pg/ml),a significant decrease in the expression level of TGF-β1(0.96±0.31 pg/ml).4.Serum concentrations of IL-10 in children with MG at different clinical stages were 0.23±0.009 pg/ml for stage I,0.20±0.007 pg/ml for stage II,0.19±0.005 pg/ml for stage III,and 0.18±0.003 pg/ml for stage IV,phaseⅤ0.16±0.001 pg/ml.The concentrations of TGF-β1 were 0.70±0.008pg/ml in stageⅠ,0.67±0.006pg/ml in stageⅡ,0.56±0.005pg/ml in stageⅢ,0.51±0.004pg/ml in stageⅣand 0.42±0.002pg/ml in stageⅤ.The levels of IL-10 and TGF-β1decreased with the severity of the disease.Conclusion:1.The number of Bregs in serum of children with MG and the expression level of IL-10 and TGF-β1 secreted by these Bregs were all significantly lower than that in control group.In addition,the number of Bregs and the expression level of IL-10 and TGF-β1in serum of children and were correlated with the clinical stage of MG.2.The number of Bregs and the expression level of IL-10 and TGF-β1 in serum of children with MG could be used to further understand the pathogenesis of MG and to provide theoretical and experimental basis for further clinical diagnosis and treatment.