Evaluation of the Efficacy and Safety of Satralizumab in a Pregnant <scp>NMOSD</scp> Patient With <scp>AQP4</scp> / <scp>MOG</scp> ‐ <scp>IgG</scp> Dual Seropositive: A Case Report

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a chronic autoimmune neuroinflammatory disease, typically characterized by antibodies against aquaporin 4 (AQP4-IgG) or myelin oligodendrocyte glycoprotein (MOG-IgG). Simultaneous seropositivity for both antibodies in a single patient is exceedingly rare. We present a dual AQP4-IgG/MOG-IgG seropositivity case who was treated with satralizumab throughout the whole preconception-to-postpartum course, to evaluate the effectiveness and safety of satralizumab, especially during the perinatal period. A 34 year-old female, initially presenting with decreased visual acuity in the left eye, was diagnosed with NMOSD as both AQP4-IgG and MOG-IgG seropositive. With traditional treatment of corticosteroids and mycophenolate mofetil, her vision gradually recovered and overall condition stabilized. Due to the desire for conception, her treatment regimen was transitioned to satralizumab monotherapy. Three months later with five doses of satralizumab, she successfully conceived and delivered a healthy female infant at 38 weeks' gestation. Satralizumab treatment was continued throughout the preconception-to-postpartum course. All routine and perinatal assessments were within normal limits, and 4 months postpartum, the condition of both mother and child remained stable, further supporting the favorable effectiveness and safety of satralizumab in this case. The coexistence of AQP4-IgG and MOG-IgG in an NMOSD patient represents an extremely rare and complex clinical scenario. When fertility is desired, the selection of disease-modifying therapy must carefully balance effectiveness and safety. In such cases, satralizumab may serve as a viable option, supported by promising real-world data.