Combination Of Anti-early Apoptotic Cell Autoantibodies And Anti-SSA Autoantibodies In Lupus Nephritis

Background Autoantibodies against early apoptotic cells have been detected in a subset of SLE patients,SSA was suggested to be the major auto antigen.We aimed to investigate the associations of anti-early apoptotic cell autoantibodies with the presence of anti-SSA,anti-SSB,the clinical features and short-term outcomes of lupus nephritis.Methods Multiparameter flow cytometry was used to select early apoptotic cells and measure the simultaneous binding of annexin V,7-AAD,and IgG from lupus nephritis(n=39).Associations of autoantibodies against early apoptotic cells with the presence of anti-SSA,anti-SSB,and the clinical features were further investigated.Results 33.3%(13/39)LN patients were positive for autoantibodies against early apoptotic cells.Both the prevalence of anti-SSA and anti-SSB were similar between patients with and without anti-early apoptotic cell autoantibodies(9/13 vs.15/26,3/13 vs.4/26).Anti-early apoptotic cell antibody positive patients had lower C3 levels and significantly higher anti-dsDNA levels as compared with anti-early apoptotic cell antibody negative patients(0.34 ± 0.22 vs.0.47 ± 0.17,P=0.059;502.99 ± 275.48 vs.214.13 ± 229.29,P=0.001).In univariate logistic regression analysis,the presence of anti-early apoptotic cell antibody at baseline could predict poor short-term prognosis(HR 7.500,95%CI:1.210-46.504,P=0.030),while patients who were double positive for anti-SSA and anti-early apoptotic cell antibody at baseline had a significantly increased risk of poor short-term outcome(HR 17.500,95%CI:2.500-122.500,P=0.004).Conclusion Anti-early apoptotic cell antibodies,combined with anti-SSA antibodies at baseline,might be predictors of poor short-term outcome in lupus nephritis.