Inflammatory myopathies.

New information regarding myositis specific autoantibodies, histopathologic analysis of muscle biopsy specimens, and immunogenetic features of the different serologic subsets of disease has greatly increased our understanding of the pathogenesis of the inflammatory myopathies. The clinical descriptions of inclusion body myositis and 'amyopathic dermatomyositis' (Euwer and Sontheimer, 1993) are examples of our expanded descriptive capabilities in the evaluation of patients with myopathy. Finally, newer techniques such as cytokine analysis and magnetic resonance imaging may help in the ongoing assessment of disease activity in patients with myositis. The combination of these recently described clinical and laboratory parameters are enough to force a reconsideration of the previously described classification and diagnostic criteria in the inflammatory myopathies.