Hepatitis C virus (HCV) reactivation caused by steroid therapy for dermatomyositis.

A Japanese woman was treated with injectable methylprednisolone and oral prednisolone for dermatomyositis. On admission, her serum was positive for anti-hepatitis C virus (HCV) antibodies, although HCV RNA was undetectable on polymerase chain reaction. Glucocorticoid therapy improved the dermatomyositis; however, the serum alanine aminotransferase levels rapidly increased, with positive serum HCV RNA and a high viral titer. Both parameters decreased in association with prednisolone tapering, whereas dermatomyositis subsequently recurred and the administration of glucocorticoid therapy was repeated. The serum alanine aminotransferase and HCV RNA levels subsequently increased in a similar manner to that observed after the first course of therapy. Liver enzymes and the viral load should be monitored in anti-HCV-positive patients receiving immunosuppressives, even if serum HCV RNA is negative.