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.

Post-vaccination MDEM associated with MOG antibody in a subclinical Chlamydia infected boy

The mechanism of post-vaccination acute disseminated encephalomyelitis (ADEM) has been hypothesized as resulting from vaccination-injected antigens cross-reacting with myelin components, however, a precise etiology has been uncertain. In this report, we describe the case of a 6-year-old Japanese boy who had multiphasic disseminated encephalomyelitis (MDEM), and was positive for both anti-myelin oligodendrocyte glycoprotein (MOG) antibodies and Chlamydophila pneumoniae antibodies. After vaccinations that were the second one for measles and rubella, and the booster immunization for Japanese encephalitis, the patient presented with fever, headache, vomiting, and a change in personality. He was treated with a high-dose of intravenous methylprednisolone in the diagnosis of ADEM. However, these symptoms recurred with different magnetic resonance imaging lesion, and he was diagnosed as MDEM. Retrospective testing for pathogens revealed C. pneumoniae IgM and IgG antibodies, and it was considered that he was infected with C. pneumoniae subclinically. The patient's serum indicated a positive response for the anti-MOG antibody from the onset of the ADEM diagnosis and in all recurrent episodes. Chlamydia species infection has been known to play a role in demyelinating diseases. It is also known that the anti-MOG antibody may be present but not exhibit its pathogenesis in the absence of a cell-mediated inflammatory response; however, the precise mechanism of action of the anti-MOG antibodies is not yet determined. We propose the possibility that post-vaccination demyelinating disease may result from the synergistic effects of a preceding anti-MOG antibody, possibly produced in response to a subclinical Chlamydia species infection.