Efgartigimod for Anti-n-Methyl-d-Aspartate Shanxi Provincial People's Hospital, Taiyuan, China Receptor Encephalitis: A Case Report and Literature Review.

INTRODUCTION: Neonatal Fc receptor (FcRn) antagonists can improve autoimmune diseases such as myasthenia gravis by rapidly and selectively reducing serum IgG levels, and they hold potential for broader applications in other autoimmune disorders. CASE PRESENTATION: We report a 32-year-old female admitted with psychiatric and behavioral abnormalities, who tested positive for anti-NMDA receptor antibodies indicative of autoimmune encephalitis. Despite first-line therapy with corticosteroids and intravenous immunoglobulin, her cognitive dysfunction progressively worsened, ultimately rendering her unable to communicate. Following four administrations of efgartigimod, the patient exhibited rapid and marked clinical improvement. CONCLUSION: This review highlights the potential of FcRn antagonists as an additional therapeutic option in clinical practice.