小児重症筋無力症の診療

Treatment of Juvenile Myasthenia Gravis

小児発症重症筋無力症の病態は成人発症と変わらないが，眼筋型が主体，低い抗体陽性率，低い胸腺腫合併率，高い寛解率などの点で成人発症例と大きく異なる。成人の治療方針である低用量ステロイド，非経口速効性治療戦略のエビデンスは小児において十分でなく，免疫抑制薬の安全性も確立していない。むしろ，十分な量のステロイド使用により，寛解率が高いことが報告されているため，成人の治療方針との乖離が生じている。

Abstract

The pathogenesis of juvenile myasthenia gravis is similar to that of adult-onset cases, but does differ significantly in that it is predominantly ocular type, has a low antibody-positive rate, a low thymoma complication rate, and a high remission rate. The evidence for the adult treatment strategy of low-dose steroids and fast-acting treatment is insufficient in children, and the safety of immunosuppressive drugs has not been established. Steroid use in children in particular requires caution due to the risk of growth retardation, and while lower doses are desirable, the efficacy of lower doses has not been as fully investigated as in adults. Conversely, experience has shown that the use of adequate doses of steroids results in high remission rates, and there is currently no rationale for recommending lower doses.