In this study, we aimed to assess the levels of B cell activating factor from the tumor necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL) in cerebrospinal fluid (CSF) of patients with anti N-methyl-oaspartate receptor (NMDAR) encephalitis and determine their correlation with clinical outcome. BAFF and APRIL concentrations in CSF and serum from 40 patients with anti-NMDAR encephalitis and 20 controls were measured by enzyme-linked immunosorbent assay (ELISA). Compared with controls, the levels of both BAFF and APRIL in CSF were significantly increased in patients with anti-NMDAR encephalitis (p < 0.001 and p < 0.001). Patients with unfavorable outcome had higher levels of BAFF and APRIL in CSF than those who had favorable outcome (p < 0.05 and p < 0.05). BAFF and APRIL levels in CSF were elevated and associated with clinical outcome in patients with anti-NMDAR encephalitis, indicating that they may be valuable biomarkers to this disease. (C) 2017 Elsevier B.V. All rights reserved.