Background: Neuromyelitis optica (NMO) is an autoimmune disease of the central nervous system (CNS) associated with a specific autoantibody, anti-aquaporin-4 antibody (AQP4-Ab). Although low-dose corticosteroids and immunosuppressants are widely used for prevention in NMO, the efficacy is not yet confirmed by large controlled studies. Objective: To evaluate the benefit of low-dose prednisolone therapy in patients with relapsing NMO. Methods: We retrospectively reviewed the medical records of consecutive NMO patients admitted to Tohoku University Hospital from January 2000 to December 2009. NMO is defined as CNS inflammatory disease with serum AQP4-Ab. We reviewed their treatment for the past decade, and evaluated the relation to their mean annual relapse rate. We also evaluated annual relapse rate and Expanded Disability Status Scale (EDSS) scores of prednisolone pretreatment period and prednisolone posttreatment period in selected patients. In addition, we evaluated the relation between relapse and dose or duration of prednisolone therapy. Result: 46 patients were identified to have serum AQP4-Ab. Among them, four patients were excluded from this study because of incomplete medical records. The mean age of the 42 patients was 41.7 years (range, 13-73 years), and the mean disease duration was 10.7 years (range, 0.5-29.0 years). The prevalence rate of prednisolone use increased from 13.7 % to 84.5% in the past decade. On the other hand, their mean annual relapse rate decreased from 0.75/year to 0.12/year. Twenty-five NMO patients, who had more than six months history of both prednisolone pretreatment period and posttreatment period, were selected for further study. The mean annual relapse rate was lower in posttreatment period than in pretreatment period (0.15/year and 0.94/year respectively, P<0.001). Median EDSS score was 5.0 in both periods. Relapses were observed frequently in patients who reduced prednisolone less than 10 mg/day within 18 months. Conclusions: In NMO, treatment with low-dose prednisolone is effective to reduce the relapses and to maintain their function. We recommend using more than 10mg/day of prednisolone for at least 18months for the effective treatment of NMO.
Read More: The efficacy of low-dose prednisolone in neuromyelitis optica