Bridging to low-dose corticosteroids after satralizumab discontinuation in unplanned pregnancy: Two cases of AQP4-positive NMOSD.

BACKGROUND

Satralizumab is effective for relapse prevention in AQP4-positive neuromyelitis optica spectrum disorder (NMOSD), but its safety during pregnancy has not been established. While several cases have reported continued satralizumab use in planned pregnancies, the management of unplanned pregnancy in patients already on satralizumab remains undefined.

CASES: We report two AQP4-positive NMOSD patients (aged 32 and 21 years) who conceived unexpectedly during satralizumab maintenance therapy (8 and 7 months of treatment, respectively). Upon pregnancy confirmation, satralizumab was discontinued. Both patients received low-dose corticosteroid monotherapy throughout gestation as bridging maintenance: one with methylprednisolone 4 mg/day, the other with prednisolone 10 mg/day. No NMOSD relapses occurred during pregnancy. Both delivered healthy full-term neonates without congenital anomalies. Satralizumab was resumed immediately postpartum, with no relapses during follow-up.

CONCLUSION

Among two AQP4-IgG-positive NMOSD patients with sustained pre-conception remission who experienced unplanned pregnancy during satralizumab maintenance, switching to low-dose corticosteroid monotherapy after drug cessation coincided with relapse-free gestation. The strategy avoids fetal exposure to satralizumab with unconfirmed gestational safety, yet the benign clinical course cannot be solely attributed to steroid bridging. Persistent residual satralizumab activity, inherent long-term disease quiescence, and pregnancy-mediated immune shifts all likely contributed to the stable disease state. These paired clinical observations only generate preliminary hypotheses and cannot support broad clinical recommendations for pregnant NMOSD patients.