Recombinant interferon-beta therapy and neuromuscular disorders

Interferon-beta (IFN beta) is an extra-cellular protein mediator of host defense and homeostasis. IFN beta has well-established direct antiviral, antiproliferative and immunomodulatory properties. Recombinant IFN beta is approved for the treatment of relapsing-remitting multiple sclerosis. The immunomodulatory effects of IFN beta administration failed to demonstrate consistent benefit during treatment of various autoimmune neuromuscular diseases. Existing studies were flawed due to the often uncontrolled and unblinded nature of protocols, small patient numbers per study, the undetermined optimum dose and schedule of IFN beta therapy, and the relatively brief periods of IFN beta administration and clinical follow-up for mostly chronic inflammatory disorders. Additional, controlled, prospective studies are needed to definitely establish the full potential of this cytokine for this group of diseases. IFN beta therapy may trigger autoantibody production, but only rarely clinically overt autoimmune disease. Anecdotal reports hint at the exceptional association between IFN beta treatment and the induction or exacerbation of a variety of immune-mediated neuromuscular diseases, likely in genetically predisposed individuals. Thus, recombinant IFN beta has the theoretical potential to either treat or cause autoimmune neuromuscular disorders by altering the complicated and delicate balances within the immune system networks. (C) 2009 Elsevier B.V. All rights reserved.