When Rituximab or Cyclophosphamide Did Not Achieve Adequate Improvement in Severe NMDA Receptor Antibody Encephalitis in Children

This protocol addresses children under 18 years with NMDA receptor antibody encephalitis classified as severe who did not achieve adequate improvement approximately 1–3 months after second-line immunotherapy. The following outlines the clinical situation and the direction of the next treatment step.

Patient scenario

Children (age <18 years) with NMDA receptor antibody encephalitis and severe disease classification. Severe is defined by issues affecting safety and function. Any one or more of the following severity markers classifies the disease as severe: intensive care requirement, need for airway support, dysautonomia threatening safety, being bed bound, suicidal ideation, or adapted mRS score 4–5.

Why this step is reached — prior therapy did not meet its goals

This protocol is reached when the previous treatment step — cyclophosphamide (where rituximab was used first, or vice versa), and/or escalation to tocilizumab in the most refractory patients — did not result in adequate improvement at reassessment approximately 1–3 months after treatment.

Direction at this stage

The approach at this stage centres on sustained maintenance immunosuppression extending beyond six months. The complete structured regimen — including which agents apply, the conditions governing each choice, and how availability and clinical response shape the decision — is set out in the full protocol.

Instant Access to Structured Evidence-Based Regimens

References

DOI: 10.1212/NXI.0000000000001052

Severe is defined by issues affecting SAFETY and FUNCTION.

Any (≥1) of the severity markers present below (items a-i) scoring “severe” rather than “standard” would classify as severe disease.

Maintenance (>6 mo) immune suppression can be considered in any patient who fails to improve adequately despite conventional second-line or escalation therapy.

RTX redosing (when repopulation of CD19 occurs) and MMF are appropriate treatments if maintenance (>6 mo) immune suppression is required.

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