Initiation of rituximab therapy for new onset neuromyelitis optica spectrum disorder during pregnancy.

Background: Aquaporin-4 IgG (AQ4-IgG)-neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory CNS disease that is predominantly characterized by severe relapses of optic neuritis and longitudinally extensive transverse myelitis (LETM). Women are disproportionately affected by AQ4-NMOSD, usually with disease onset occurring between the ages of 35-45. This has significant implications during pregnancy, as disease activity in NMOSD does not remit during gestation. The optimal treatment of NMOSD during pregnancy has not been established.

Methods: Case report.

Results: A 35-year old woman, 10 weeks pregnant, presented with bilateral optic neuritis and intractable hiccups. Workup revealed seropositive aquaporin-4 IgG. She was treated with pulse intravenous methylprednisolone and plasma exchange. Because of high risk for future relapse, Rituximab 1000 mg was given at weeks 15 and 17 of pregnancy. She had no further relapses during pregnancy. She delivered her daughter at 39 weeks without complication.

Conclusion: This case demonstrated a favorable outcome in administering rituximab for NMOSD with disease onset during pregnancy. This description of therapy for disease onset during pregnancy is novel, and adds to the few existing case reports of administering rituximab during pregnancy.