This study evaluates the efficacy of erythropoietin in refractory autoimmune encephalitis. Ten patients will receive 100 IU/kg of erythropoietin 3 times a week for 12 weeks.

Erythropoietin can improve the refractory autoimmune encephalitis. Erythropoietin has tissue-protective effect via activation of Janus kinase (JAK)-2, signal transducer and activator of transcription (STAT)-5 pathway and NF-kappa B pathway. The activation of JAK-2 and STAT-5 promote hemoglobin synthesis and facilitate cell cycle progression. Also, NF-kappa B pathway inhibition regulates pro-inflammatory cytokine production.

We expect that erythropoietin may lead to improve the symptoms and outcome of autoimmune encephalitis.

Inclusion Criteria:

• Clinically diagnosed autoimmune encephalitis
• Ineffective 1st line treatment (e.g. steroid IV, IVIg) and 2nd line treatment (e.g. Rituximab or cyclophosphamide)

Exclusion Criteria:

• Hemoglobin > 12g/dL
• Hematochrit >36%
• Thrombocytosis > 750K
• AST or ALT > 120
• HIV (+)
• Allergic reaction upon erythropoietin
• Uncontrolled hypertension
• mRS before the autoimmune encephalitis > 3
• Breast feeding or pregnancy
• History of ischemic stroke or pulmonary thrombosis
• Refuse to be enrolled