113 Rituximab and maintenance mycophenolate mofetil for treatment of refractory ANTI-N-METHYL-D-ASPARTATE-receptor (NMDAR) encephalitis
IntroductionNMDAR encephalitis is an autoimmune condition with antibodies to the NR1 subunit of the NMDAR. It has a variable clinical presentation with behavioural and psychiatric symptoms. There is frequently a relapsing course. A known association exists with tumours, particularly ovarian teratoma. Cases which are not associated with tumour often fail first line therapy. As such, therapy for this disease can be challenging and involves a spectrum of immunotherapy. Rituximab is widely considered to be second line treatment for this illness. We present two cases of refractory anti-NMDAR encephalitis.CasesBoth patients were confirmed antibody positive in the serum and cerebral spinal fluid. There was no tumour identified on whole body positron emission tomography and transvaginal pelvic ultrasound. Each patient was initially treated with first line therapy of intravenous immunoglobulin, plasmapheresis and methylprednisolone with limited symptomatic improvement. Second line therapy of two doses of rituximab was administered intravenously two weeks apart at a dose of 1000 mg. Mycophenolate mofetil was used at a dose of 1000 mg twice daily to minimise B-cell reconstitution. Response to treatment was monitored with measurement of CD 19+ Pan B cells in peripheral blood and clinical assessment by the consultant liaison psychiatry service. Both patients demonstrated significant response with undetectable CD 19+ Pan B cells on serial testing and sustained clinical improvement in initial behavioural symptoms.ConclusionIn patients with anti-NMDAR encephalitis, rituximab combined with maintenance mycophenolate mofetil may be an effective treatment.