Long-term outcome of a group of Japanese children with myelin-oligodendrocyte glycoprotein encephalomyelitis without preventive immunosuppressive therapy.

INTRODUCTION: There is increasing evidence that immunosuppressive therapy is essential for reducing disease activity and avoiding further attacks in patients positive for anti-myelin-oligodendrocyte glycoprotein (MOG) antibodies. However, to date, no placebo-controlled trial has been published.

OBJECTIVE: We aimed to evaluate the long-term outcome and anti-MOG antibody titers of seropositive Japanese pediatric patients without long-term immunosuppressive therapy.

METHODS: Of 11 consecutive patients positive for anti-MOG antibodies seen at Tohoku University Hospital from 1992 to 2013, 5 patients did not receive preventive long-term immunosuppressive treatment and had been followed up longitudinally (more than 60 months).

RESULTS: The follow-up periods were 68-322 months (median, 150 months). The expanded disability status scale scores of all patients were 0 at the last observation. Three patients were negative for the antibody at the last follow-up, and the titers of the two patients whose anti-MOG antibodies were positive at the last follow-up were lower than at the first examinations. The interval to the second attack in three patients was 1-124 months (median, 33 months). Acute attacks were treated with methylprednisolone pulse therapy (four patients) or intravenous immunoglobulin (one patient). All patients achieved full recovery after acute therapy. Oral corticosteroid was tapered over a period of 6-26 weeks (median, 17 weeks).

CONCLUSIONS: We reported our experience with very long-term follow-up of 5 Japanese pediatric patients with anti-MOG antibody-positive disease who did not receive long-term immunosuppressive therapy. Persistent positivity to anti-MOG antibody in some patients suggests the necessity for long-term follow up despite infrequent relapse.