Ofatumumab, a Fully Human Anti-CD20 Monoclonal Antibody, in the Treatment of Severe Refractory Anti-N-methyl-D-Aspartate Receptor Encephalitis: Two Case Reports

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is a type of autoimmune encephalitis (AE) characterized by antibodies against NMDA receptor. As the most common AE, anti-NMDAR encephalitis affects 54% ~ 80% of patients with AE. It is associated with a high percentage of severe illness. It typically manifests as behavioral and psychiatric disturbance, epilepsy, cognitive decline, decreased level of consciousness, involuntary movements, autonomic dysfunction, central hypoventilation, etc. We report two refractory anti-NMDAR encephalitis. One of them describes a case of anti-NMDA encephalitis coexisting with MOG antibodies. The two patients were administered first-line therapy with glucocorticoids and intravenous immunoglobulin but did not improve clinically. Therefore, the patient was switched to the fully human anti-CD20 monoclonal antibody, ofatumumab. Their consciousness, behavioral and psychiatric disturbance, and capacity to conduct daily tasks improved markedly after sequential therapy with ofatumumab, as demonstrated by the modified Rankin scale (mRS) score. For the first time, we report a successful approach to the treatment of refractory anti-NMDAR encephalitis using the fully human anti-CD20 monoclonal antibody ofatumumab, which serves as an important reference for the treatment of AE.