Persistence of anti-NMDAR antibodies in CSF after recovery from autoimmune encephalitis

Excerpt

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is characterized by psychiatric and neuropsychiatric manifestations preceded by prodromal symptoms in about 70% of patients. It can occur as an autoimmune antibody-mediated non-paraneoplastic syndrome or as a paraneoplastic disorder, triggered by different tumors, more often an ovarian teratoma. NMDARs are localized in neuronal post-synaptic membranes and play a role in synaptic transmission and plasticity. In vitro and in vivo investigations confirm that anti-NMDAR antibodies cause a selective and reversible decrease in NMDAR surface protein directly associated with the level of the antibody titers [1]. Anti-NMDAR antibodies can be detected in the cerebrospinal fluid (CSF) and serum of affected patients, but often they are found only in the CSF. Previous data have confirmed that anti-NMDAR antibodies are more frequently present in both serum and CSF in patients with ovarian teratoma than in subjects without a tumor, suggesting that they can act as a trigger of autoimmune process [2]. In anti-NMDAR encephalitis, the correlation between antibody titers, relapses, and outcome is currently unclear. …