Myasthenia gravis during low-dose IFN-alpha therapy for chronic hepatitis C.

We describe the case of a 56-year-old man who had high aminotransferase levels and anti-hepatitis C virus (HCV) antibodies. He underwent liver biopsy and biochemical screening to evaluate whether he would benefit from interferon (IFN) treatment. The patient was discharged with a diagnosis of HCV-related active chronic hepatitis, skin porphyria, and type 2 diabetes. On December 5, 1995, he began therapy with recombinant IFN-alpha at a dose of 3 MIU three times a week. He stopped this therapy in February 1996 because of asthenia, diplopia, headache, and anxiety. During IFN therapy, he had normal aminotransferase levels and no detectable HCV RNA, a condition that persists to the present. Between March and May 1996, the patient was admitted several times to a neurology clinic, where myasthenia gravis was diagnosed and treatment with pyridostigmine and cyclosporine was initiated. This case and others indicate that caution should be exercised in administering IFN because low doses can be correlated with myasthenia gravis in patients without malignancies.