ObjectiveTo explore the clinical features of myasthenia gravis (MG) harboring both acetylcholine receptor antibody (AChRAb) and muscle-specific tyrosine kinase antibody (MuSKAb) positivity.MethodsWe searched PubMed, Web of Science, Embase and China National Knowledge Infrastructure databases (from inception to November 2016), to collect the case reports of MG with both AChRAb and MuSKAb positivity. Along with one case discovered in Department of Neurology, West China Hospital, the clinical data of the cases were retrospectively analyzed.ResultsA total of 13 double-seropositive MG patients were enrolled in this study, demonstrating a marked female predominance (including 1 male and 12 females) and a younger age at onset [(31.07±24.77) years]. During the disease course, 10 of the included patients presented severe bulbar involvement, dyspnea and neck weakness, with myasthenic crisis in 6 individuals. Among the 11 patients with detailed records, abnormal thymus glands comprised 4 thymus hyperplasia and one thymoma. While the response to oral pyridostigmine was unsatisfactory in 11 double-seropositive MG patients, ranging from mild benefit to overt intolerance; the patients treated with plasma exchange (3/3), rituximab (1/1) or corticosteroid (7/12) improved dramatically, with other immumosuppressants and intravenous immunoglobulin partially responsive. Moreover, 5 patients undergoing thymectomy improved markedly or partially.ConclusionsCompared with MG patients with MuSKAb positivity merely, the condition of the double-seropositive MG patients seem to be more severe and further inclined to myasthenic crisis. The incidence of abnormal thymus, such as thymus hyperplasia, is higher. Thymectomy may be an effective treatment for such patients.
