Expression Of Circulating B Cell Subsets And Related Clinical Significance Of IgA Nephropathy Patients

Background:The pathogenesis of IgA nephropathy(IgAN)is affected by many factors,such as environment,heredity and immunology.With the development of research,it has been confirmed that IgAN is an autoimmune disease.Both innate immunity and adaptive immunity are involved in the pathogenesis of IgAN.However,the role of B cell-mediated humoral immunity in the pathogenesis of IgAN remains unclear.In this study,we preliminarily investigated the relationship between the frequency of circulating B cell subsets and the occurrence and progression of IgAN.Methods:In this study,20 patients with IgAN and 11 age and sex matched HC were recruited.The frequency changes of circulating B cell subsets were measured by flow cytometry.The concentration of plasma cytokine IL-6 was determined by the cytometric bead array(CBA).Statistical methods were used to analyze the differences of the above-mentioned cells and cytokines between the experimental group and the control group and the relationship between them and the clinical indicators.Changes in circulating B cell subsets and clinical markers in patients with IgAN after 8-12 weeks of glucocorticoid treatment were measured.Results:1.Compared with the HC group,the frequency of circulating unswitched memory B cells and plasmablasts was increased in IgAN patients.In addition,There is a positive correlation between circulating unswitched memory B cells and plasmablasts.2.The frequency of unswitched memory B cells and plasmablasts was positively correlated with the level of 24-hour urinary protein.3.Serum IL-6 concentration was increased IgAN,and was positively correlated with unswitched memory B cells and 24-hour urinary protein level,while negatively correlated with EGFR level.4.After 8-12 weeks of glucocorticoid treatment,the frequency of unswitched memory B cells and plasmablasts decreased significantly.But plasma IL-6 levels did not change.Conclusions:1.Unswitched memory B cells may participate in the pathogenesis of IgA nephropathy through differentiation into plasma cells.2.After glucocorticoid treatment,the frequency of unswitched memory B cells in patients with IgA nephropathy decreased,supporting its involvement in the pathogenesis of IgA nephropathy.3.The frequency of unswitched memory B cells decreased significantly,suggesting that unswitched memory B cells can be used as a biomarker to evaluate the progression of IgAN and treatment effect.