ABSTRACT
Objective In this study, we constructed a plasmid, specifically expressed SUMO protein, and to study the expression level of anti-SUMO antibody in the serum of patients with primary biliary cholangitis, systemic lupus erythematosus, rheumatoid arthritis, Connective tissue disease, sjogren′s syndrome which were typical of autoimmune diseases.And to investigate whether anti-SUMO antibodies can be used as specific serum markers of PBC.Methods Plasmids containing SUMO1, SUMO2 and SUMO3 fragments were prepared by PCR and ET cloning and introduced into E.coli for protein induction and purification, respectively.Dot blot was used to preliminarily screen anti-SUMO antibody-positive specimens from serum samples of PBC patients and were verified by western blot to obtain positive reference serum.Through the establishment of the optimal anti-SUMO antibody ELISA diagnostic system, the positive rates of three subtypes of anti-SUMO antibody in PBC, SLE, SS, RA and CTD were detected, and their differences were analyzed by chi-square test.ResultsThe anti-SUMO antibody label has a specificity of up to 99％in PBC and a sensitivity of around 86％.After chi-square test analysis, the positive detection rate of anti-SUMO antibody in PBC was higher than that of nonPBC autoimmune disease and healthy controls (P＜0.01).There was no significant difference in the expression of anti-SUMO antibody in other autoimmune disease populations (non-PBC autoimmune diseases) (P＞0.05).Conclusion The highly specific anti-SUMO antibody is expected to become a novel antibody for diagnosis of PBC, which is of great significance for improving the clinical diagnosis efficiency of PBC.