[Correlation between oral corticosteroid therapy and present disease status in myasthenia gravis]

The aim of this study was to delineate the status of oral corticosteroid therapy in myasthenia gravis (MG), and to elucidate the effectiveness of oral corticosteroids according to dosing regimen. We evaluated 472 MG patients from 11 neurological centers in Japan. Disease severity was determined according to MGFA, QMG and MG composite. Clinical state following treatment was categorized according to MGFA postintervention status. We also completed the Japanese version of the 15-item MG-specific QOL scale (MG-QOL15-J). The statistical analysis revealed that achievement of minimal manifestation (MM) or better status using maximum prednisolone (PSL) dose or reduced PSL dose by 25% or more after adding calcineurin inhibitors had significantly positive effects on the present QMG, MG composite and MG-QOL15-J. The maximum dose and administration period of PSL did not influence present disease severity, but administration period of PSL ≥20 mg mg/day had negative effects on the present QOL. Achieving a status of MM or better by maximum PSL dose or reduced PSL dose combined with other agent may improve the present MG status and QOL.