[Systemic manifestations of idiopathic inflammatory myopathies--part one].
Dermatomyositis and polymyositis are the idiopathic inflammatory myopathies of autoimmune origin. Apart from muscle weakness, general symptoms such as the affection of visceral organs and altered indicators of humeral immunity occur in a minority of patients. The aim of the study was to establish whether the systemic manifestations of the disease, altered immunoserologic parameters and findings of muscle vasculitis occurred more frequently in patients with dermatomyositis or polymyositis. The frequency of clinic, serologic and histopathologic alterations in the groups of patients with dermatomyositis and polymyositis was determined. In order to determine the degree and importance of the frequency, the following parameters were calculated: the relative rations of frequencies and the importance of the difference in frequencies of particular alterations between the groups of patients. It was found that extramuscular manifestations of the disease such as arthritis, pulmonary, cardiac and renal changes, the increased activity of C3 and C4 complement components as well as vasculitis of muscle and skin tissue occurred more frequently in patients with dermatomyositis. This finding indicates that patients with DM, regardless of the degree of muscular affection, may have a more severe clinical course of the disease and a poor prognosis.