[A case of thymoma-associated myasthenia gravis with antibodies against interferon-alpha--a clinico-immunological follow up of the symptoms and its titer].

A 73-year-old woman developed myasthenia gravis (MG) with thymoma. She had a very high level of serum antibodies against interferon-alfa (IFN-alpha). We observed the changes to her clinical symptoms and titer of the antibody during therapeutic course. Although she underwent thymectomy, intravenous methylprednisolone therapy, and oral tacrolimus administration, MG symptoms of the patient were not significantly improved and the antibody titer remained at a high level. IFN-alpha is a potent immunomodulating cytokine that regulates MHC class II expression on antigen presenting cells and activities of NK cells, B cells, and helper/suppressor T cells. This case suggests that IFN-alpha related immunological perturbation participates in the pathogenesis of thymoma-associated myasthenia gravis.