Low-dose rituximab for the treatment of anti-NMDAR encephalitis in children: a case series study.

Abstract

Background and purpose: Rituximab is a widely used second-line immune drug for the treatment of anti-NMDAR encephalitis in patients who fail to improve approximately 2 weeks after the initiation of first-line therapies (corticosteroids, intravenous immunoglobulin, plasma exchange). The aim of this study was to investigate the efficacy and safety of low-dose rituximab in the treatment of autoimmune encephalitis in children.

Methods: This case series included 6 hospitalized children without tumors with anti-NMDAR encephalitis from January 2018 to December 2020. These children were treated with low-dose rituximab (100 mg, once weekly, according to peripheral blood CD19 + B-cell levels, 3-4 cycles, until CD19 + B cells in peripheral blood were cleared) approximately 2 weeks after the initiation of 2 or more first-line immunotherapies.

Results: After 3-4 cycles of low-dose rituximab (100 mg) treatment, the mRS score and CD19 + B-cell count decreased significantly, and the patients maintained stable neurological function (mRS ≤ 2). No adverse events resulting from infusion or other adverse reactions occurred in any patient.

Conclusion: In children with autoimmune encephalitis without tumors for whom first-line immunotherapy is ineffective, low-dose rituximab effectively reduces peripheral blood CD19 + B-cell counts, improves the clinical symptoms of patients and reduces hospitalization expenses. RCTs with sufficient sample sizes are needed to firmly establish the value of low-dose rituximab therapy for treating anti-NMDAR encephalitis in children.