The Abnormal Expression And Significance Of Bach2 In Systemic Lupus Erythematosus

Backgrounds and Objective:Bach2 is an important transcription repressor which takes part in regulating the signal pathway in several immune cells including B lymphocyte、T lymphocyte、macrophage and so on.Bach2 plays a key role in innate immunity and adaptive immunity.The abmormal express of Bach2 is responsible for many Immune-related diseases such as rheumatoid arthritis、asthma、type 1 diabetes、type 2 diabetes、Cohn’s disease.Systemic lupus erythematosus(SLE)is an autoimmune disease involving multiple systems.Its clinical manifestation is diverse and the course of disease is repeated.The pathogenesis of SLE is complex,one of the most important immune pathophysiological abnormalities are B cell over-activation and proliferation,then self-reactive B cell clearance disorders,and produce a variety of autoantibodies.At present,there is no literature on Bach2 in the pathogenesis of SLE.In order to find out the possible molecular mechanism of Bach2 in the pathogenesis of SLE,this study mainly observed the changes of Bach2 expression in B cells and their subsets of SLE patients and its relationship with disease activity.Contents and Methods:We recruited untreated SLE patients and sex and age matched healthy controls(HC).Flow cytometry was used for detecting the expression of Bach2 in the cytoplasm of peripheral blood CD19+B cells and its subgroup,and also the expression of total Bach2(cytoplasmic and nucleus)of peripheral blood CD19+B cells and its subgroup.Then we evaluated the correlation between Bach2 expression and SLE clinical parameters in the cytoplasm or in the cytoplasmic and nucleus.Results:1.The MFI of Bach2 in cytoplasm of CD 19+B cells in SLE patients(1481.0±151.2,n=12)was higher than that in healthy controls(958.9 ± 75.19,n=14),the difference was statistically significant(p=0.004<0.05).The MFI of Bach2 in cytoplasm of peripheral blood CD 19+B cells was positively correlated with SLEDAI scores(r=0.796,p=0.002),but had no significant correlation with the level of Complement C3 levels(p=0.376)and anti-double-stranded DNA antibody levels(p=0.080).2.The MFI of Bach2 in cytoplasm of CD 19+B cells subsets(CD19+IgD-CD38int/hi plasma cells,CD19+IgD+CD38int/hi immmature B cell,CD19+IgD+CD381ow/-naive B cells,CD19+IgD-CD381ow/-memory B cells)in SLE patients was higher than that in healthy controls,the difference was statistically significant(each p value was 0.048、0.005、0.011、0.005).The MFI of Bach2 in cytoplasm of CD19+B cells subsets in SLE patients was positively correlated with SLEDAI scores(each r value was 0.790、0.680、0.830、0.683,each p value was 0.002、0.015、0.001、0.014),but had no significant correlation with the level of Complement C3 levels(each r value was-0.386、-0.370、-0.267、-0.323,each p value was 0.215、0.236、0.402、0.306)and anti-double-stranded DNA antibody levels(each r value was-0.574、-0.151、-0.469、-0.582,each p value was 0.051、0.639、0.124、0.057).3.The MFI of total Bach2(cytoplasmic and nucleus)of peripheral blood CD19+B cells in SLE patients(1301.0±94.1,n=13)was not significantly different from that of healthy controls(1425.0±126.2,n=17).The MFI of total Bach2 of peripheral blood CD19+B cells in SLE patients was not significantly correlated with SLEDAI scores(p=0.881),Complement C3 levels(p=0.638)and anti-double-stranded DNA antibody levels(p=0.820).4.The MFI of total Bach2 of CD19+B cells subsets(CD 19+IgD-CD3 8int/hi plasma cells,CD 19+IgD+CD3 8int/hi immmature B cell,CD19+IgD+CD381ow/-naive B cells,CD19+IgD-CD381ow/-memory B cells)in SLE patients was not significantly different from that of healthy controls(each p value was 0.064、0.695、0.400、0.370).The MFI of total Bach2 of CD19+B cells subsets was not significantly correlated with SLEDAI scores(each p value was 0.881、0.716、0.830、0.466),Complement Complement C3 levels(each p value was 0.857、0.375、0.541、0.642)and anti-double-stranded DNA antibody levels(each p value was 0.415、0.997、0.990、0.602).Conclusion:The expression level of Bach2 in cytoplasm of CD19+B cells and CD19+B cells subsets in SLE patients was higher than that in healthy controls.The expression level of Bach2 in cytoplasm of peripheral blood CD19+B cells in SLE patients was positively correlated with SLEDAI scores,but had no significantly correlation with the level of anti-double-stranded DNA antibody and Complement C3 levels.Meanwhile,The expression of total Bach2 of peripheral blood CD19+B cells and CD19+B cells subsets in SLE patients was not significantly different from that of healthy controls.