Brain-Reactive Antibodies are Potential Biomarkers for Evaluating Therapeutic Efficacy in NPSLE Patients

Neuropsychiatric systemic lupus erythematosus (NPSLE) is the main cause of disability and death in systemic lupus erythematosus (SLE). It can cause cognitive impairment and organic brain syndrome. Brain-reactive antibodies, such as anti-DNA/anti-N-methyl-D-aspartate receptor (NMDAR) antibodies (DNRAbs), anti-microtubule-associated protein 2 (anti-MAP2) antibodies, and anti-glial fibrillary acidic protein (anti-GFAP) antibodies are thought to participate in the progression of NPSLE and thus considered potential diagnostic biomarkers, but whether they can be used for evaluating therapeutic efficacy in NPSLE is unknown.

Overall, 17 NPSLE patients and 10 non-SLE controls were included in this study. All the patients were treated with glucocorticoid (GC) pulse therapy. Serum and cerebrospinal fluid (CSF) concentrations of DNRAbs and anti-MAP2 and anti-GFAP antibodies were measured using enzyme-linked immunosorbent assay. The differences between the CSF concentrations of these antibodies in NPSLE patients before and after GC pulse therapy were analyzed.

CSF concentrations of DNRAbs and anti-MAP2 and anti-GFAP antibodies were significantly higher in NPSLE patients compared to the non-SLE controls. Among the patients, CSF concentration of DNRAbs was significantly higher in the patients with acute confusional state (ACS) than in those with non-ACS diffuse NPSLE or focal NPSLE. Additionally, CSF concentration of DNRAbs was significantly correlated with QIgG (r=0.4884, P=0.0467) and IgG index (r=0.5319, P=0.0280) in NPSLE patients. Moreover, CSF concentrations of DNRAbs, anti-MAP2, and anti-GFAP antibodies and QIgG were significantly decreased after GC pulse therapy in NPSLE patients.

These results indicate that CSF DNRAbs and anti-MAP2 and anti-GFAP antibodies are potential biomarkers for evaluating therapeutic efficacy in NPSLE.