Autoantibody to VASP is associated with neuropsychiatric systemic lupus erythematosus and elevated platelet level

Background: Biomarkers for diagnosis in neuropsychiatric systemic lupus erythematosus (NPSLE) are still lacking, we implemented this study to identify potential antigenic targets that are associated with the pathogenic mechanism in this disease, combining transcriptomic and proteomics approach with chemiluminescence immune assay. Methods: Transcriptomic analysis of 70 SLE patients with or without neuropsychiatric involvement was carried out to obtain NPSLE-related genes. Epitope mapping and sequence analysis were used to predict autoantigens. Then enzyme-linked immunosorbent assay (ELISA), immunoprecipitation (IP), and blotting were conducted to detect the autoantibodies. Results: Analysis of transcriptomic data indicated a set of hub genes with a close correlation to NPSLE phenotype and higher platelet (PLT) levels. Epitope prediction for corresponding protein revealed that vasodilator-stimulated phosphoprotein (VASP) was a potential autoantigen in NPSLE, as it had sequences with optimal antigen index mapped to small nuclear ribonucleoprotein (snRNP). By ELISA and IP, we confirmed that the anti-VASP antibody (Ab) was positively related to both NPSLE phenotype and PLT levels. Conclusions: Anti-VASP Ab was a novel candidate biomarker for NPSLE and might involve in its pathogenesis via coagulation and autoimmunity.