Case Report: Ofatumumab for the treatment of refractory anti-NMDAR-positive autoimmune encephalitis

This study reports three cases of refractory anti-NMDAR encephalitis patients who exhibited persistent severe neuropsychiatric symptoms after first-line immunotherapy (glucocorticoids, intravenous Immunoglobulin) and long-term (maintenance) immunotherapy (mycophenolate mofetil). These patients received subcutaneous injections of ofatumumab (OFA, 20 mg per dose), with dynamic monitoring of CD20+ B cell levels, antibody titers, imaging findings, and neurological function scores. All three patients showed significant improvement in psychiatric symptoms, cognitive function, and brain imaging after treatment, with CD20+ B cell levels rapidly declining to extremely low levels. Only one patient experienced mild bone pain and a low-grade fever, with no severe adverse events reported. Therefore, OFA provides a rapid, safe, and effective approach to alleviate symptoms in refractory anti-NMDAR encephalitis, offering a promising and well-tolerated therapeutic option for patients unresponsive to conventional treatments.