Therapeutic approaches in patients with inflammatory myopathies.

Among the group of inflammatory myopathies, dermatomyositis (DM) remains the most treatable subset responding, in the majority of the cases, to steroids, intravenous immunoglobulin (IVIg), or immunosuppressants. Inclusion-body myositis (IBM) remains the most difficult disease to treat; in uncontrolled studies immunosuppressants and steroids have not helped, and controlled trials with IVIg have been disappointing. Polymyositis (PM) is a very uncommon, although still overdiagnosed, disorder and its rarity poses difficulties in performing large-scale therapeutic studies; based on small series, however, PM seems to variably respond to immunotherapeutic interventions. The most consistent problem in the treatment of inflammatory myopathies remains the distinction of true PM from the difficult-to-treat cases of IBM, or from necrotizing myopathies and dystrophic processes where secondary endomysial inflammation may be prominent. The future in the management of PM, DM, and IBM seems promising because of the availability of new agents directed at T-cell activation molecules, cytokines, chemokines, and adhesion receptors. In IBM, the use of such immunomodulatory drugs may be combined with agents that block cytokine-enhancing amyloid or with agents that inhibit the formation and polymerization of amyloid fibrils.