Thymus histology and concomitant autoimmune diseases in Japanese patients with muscle-specific receptor tyrosine kinase-antibody-positive myasthenia gravis

摘要: Background and purpose The differences in the characteristics of thymus histology, coexisting autoimmune diseases related autoantibodies between anti-muscle-specific receptor tyrosine kinase (MuSK)-antibody (Ab)-positive myasthenia gravis (MG) patients, anti-acetylcholine (AChR)-Ab-positive MG patients are not clearly defined. Methods The types associated Abs 83 MuSK-Ab-positive nationwide were investigated compared with those AChR-Ab-positive followed at our institute (n = 83). As for thymoma, titin measured. Results Thymoma was present any but presented 21 (25.3%) amongst patients. Titin absent positive 25 (30.1%) Concomitant eight (9.6%) whom Hashimoto's thyroiditis rheumatoid arthritis predominated, whereas 22 (26.5%) had one or more concomitant which Graves' disease predominated. Conclusions Differences frequency thymoma thymic hyperplasia, autoantibody positivity indicated, suggesting that, contrast MG, does seem to be involved pathogenic mechanisms MG.