[Thymectomy and muscle antibodies in myasthenia gravis].

Background: Thymectomy as a treatment for myasthenia gravis (MG) is widely carried out as there is good clinical evidence for post-thymectomy improvement in younger MG patients.

Material And Methods: We examined the relationship between thymectomy, MG severity, the occurrence of muscle autoantibodies against acetylcholine receptor (AChR), titin, and ryanodine receptor (RyR), and pharmacological treatment in 52 early and 43 late-onset MG patients.

Results And Interpretation: Thymectomy in early-onset MG gave a rapid, highly significant, and long-lasting improvement during the first one to two years after surgery. Several patients had a remission. In late-onset MG, thymectomy did not provide the same improvement, but these patients responded well to immunosuppressive drug treatment, which was necessary in 75% of late-onset MG patients compared to only 25% of early-onset patients. The concentration of AChR, titin, and RyR antibodies did not predict the outcome of thymectomy. The occurrence of titin/RyR antibodies in late-onset MG indicated a less favorable prognosis.