Correlation Analysis Between Peripheral Blood DN B Cell Subpopulations And Disease Activity Indicators In Patients With Systemic Lupus Erythematosus

BackgroundSystemic lupus erythematosus(SLE)is a systemic autoimmune disease characterized by multiple systemic and multiple organ involvement.There are a large number of autoantibodies in patients with SLE.The etiology of SLE is still unclear but is known to be related to various factors such as genetics,sex hormones,and environment(such as viral and bacterial infections).Some studies have shown that there are a large number of antibody secreting cells(AS Cs)and high levels of autoantibodies in these patients,and the expansion of ASCs can cause the increase of disease activity.The proportion of B cell subsets in the peripheral blood of SLE patients is unbalanced.Some studies have also found that the subset of double negative B cells(DN B cells)is highly expanded in SLE patients.A study has even further identified DN B cells as precursors of ASCs through transcriptional and functional analysis.However,there are few studies on the correlation between DN B cells and clinical indicators in patients with SLE.ObjectiveThis study aims to explore the composition and the diagnostic value of peripheral blood B cell subpopulations in SLE patients and the correlation between DN B cell subpopulations and SLE disease activity indicators.MethodsThis study included 18 patients with SLE who were hospitalized in the Department of Rheumatology and Immunology of our hospital from January 2022 to April 2023,all of whom met the 1997 American College of Rheumatology(ACR)diagnostic criteria for SLE.They were evaluated by the Systemic Lupus Erythematosus Activity Index(SLEDAI),Ten healthy controls who underwent physical examination at the physical examination center of our hospital during the same period were included.Make sure these ten heathy controls have not recent infections,fever,and autoimmune diseases.Flow cytometry was used to detect the B cell subpopulations in peripheral blood of patients with SLE and healthy control groups.The ROC curve was used to analyze the efficacy of the proportion of each B cell subpopulation in SLE diagnosis,and Spearman correlation analysis was used to explore the correlation between the proportion of DN B cells and various clinical indicators of patients with SLE.ResultsCompared with healthy people,the proportion of DN B cell subset in CD19+B cells was significantly increased in SLE patients(p=0.001),while there was no significant difference in naive B cells,non-switched memory B cells,and switched memory B cells.The ROC curve analysis results showed that the proportion of DN B cells and non-switched memory B cell to CD19+B cells under the ROC curve for diagnosing SLE was 0.850(cut off value:5.815%,sensitivity:72.22%,specificity:100%)and 0.922(cut off value:6,35%,sensitivity:88,89%,specificity:90%),Combined with the proportion of DN B cells and non-switched memory B cell in CD19+B cells,the area under the ROC curve for diagnosing SLE was 0.878(sensitivity:72.2%,specificity:100%).Correlation analysis showed that the proportion of DN B cell subpopulations in CD19+B cells was negatively correlated with serum IgG levels,anti-dsDNA antibody titers,and anti-mitochondrial antibody titers(r=-0.616,p=0,006;r=-0.5111,p=0.063;r=-0.627,p=0.012,respectively).The proportion of DN B cells in CD19+ B cells was positively correlated with SLEDAI score,but there was no statistical difference(r=0.036,p=0.892).In addition,the proportion of DN B cells in CD19+B cells in SLE patients with lupus nephritis(LN)was higher than that in SLE patients without LN,but there was no statistical difference(r=0.091,p=0.803).Conclusions1,Compared with the healthy population,the proportion of DN B cell subsets in CD19+B cells in peripheral blood of SLE patients was significantly increased,while there was no significant difference among the naive B cells,non-switched memory B cell and switched memory B cell.2.The proportion of DN B cell subpopulation and non-switched memory B cell subpopulation in CD19+B cells and the combination of them have certain diagnostic value for SLE.3.The proportion of peripheral blood DN B cell subsets in CD19+B cells in SLE patients is negatively correlated with serum IgG levels,anti-dsDNA antibody titers,and anti-mitochondrial antibody titers.4.The proportion of peripheral blood DN B cell subpopulations in CD19+B cells in SLE patients is positively correlated with the incidence of LN and SLEDAI score,but there is no statistically significant difference.