Interferon alpha and neuromuscular disorders.

Interferon-alpha (IFNalpha) is a potent extracellular protein mediator of host defense and homeostasis. IFNalpha has well-established direct antiviral, antiproliferative and immunomodulatory properties. The worldwide, increasing and long-term use of IFNalpha, particularly for the treatment of chronic hepatitis C virus infection, has drawn attention to the development or exacerbation of numerous autoimmune phenomena, including a variety of neuropathy syndromes, neuromuscular junction disorders and myopathies. Management entailed withdrawal of IFNalpha therapy with supportive, immunomodulatory, and symptomatic treatment as clinically indicated. The mechanisms of IFNalpha-induced autoimmunity are incompletely understood, and likely vary depending on the inherent differences in the pathogenesis of the immune disorder on a background of patient genetic susceptibility. In addition, there is preliminary evidence from case reports and open-label studies that the immunomodulatory effects of IFNalpha may have potential as a treatment option for a spectrum of immune-mediated neuromuscular diseases, but further studies are needed.