[Current status and future prospects of therapy for myasthenia gravis: considering thymectomy]

The benefits of thymectomy in non-thymomatous patients with myasthenia gravis (MG) remain controversial. The first detailed case of thymectomy in a patient with MG was reported in 1939, following which many cases were published. In 2000, Gronseth and Barohn reported the first meta-analysis of the effectiveness of thymectomy in MG patients without thymoma. They reviewed 28 papers systematically and reached these conclusions: (1) The benefit of thymectomy in non-thymomatous autoimmune MG has not been conclusively established, and (2) a well-designed controlled trial is essential. Following this report, Newsom-Davis et al. designed a thymectomy trial for non-thymomatous MG patients receiving prednisone (the MGTX study). Their study compared extended trans-sternal thymectomy (ETTX) combined with prednisone and prednisone alone groups with the aim to answer 3 questions: (1) Is the former more effective in improving myasthenic weakness? (2) Does the former require a lower total dose of prednisone, and thus decrease the likelihood of concurrent and long-term toxic effects? (3) Does the former enhance patients' quality of life by reducing adverse events and symptoms associated with the therapy? Currently, 67 centers, including our institute, are involved in this study. In total, 106 patients have been enrolled (the recruitment goal is 150). The patients are scheduled for a 5-year follow-up. The MGTX study will offer new information on the role of thymectomy in improving the quality of life of patients with MG.