Serological Aspects of Myositis

Idiopathic polymyositis is a chronic inflammatory systemic disease with preponderant infestation of the musculature. Dermatomyositis also involves skin participation (Conrad et al., 2001c; Kalovidouris, 1992; Mimori, 1996). Idiopathic, secondary and paraneoplastic forms of the disease can also be observed. The first report about myositis was given in 1863 by Wagner (Wagner, 1863). Also Unverricht (Unverricht, 1887) reported in 1887 about a case about Myositis, and introduced the concept of dermatomyositis in 1891. In addition, distinct forms of interstitial myositis, marked by an appearing from foci of inflammation in the muscular interstitium and causative organism conditioned Myositis can be observed. The cause-conditioned myositis can be driven by Toxoplasma gondii or Trichinella spiralis infections (parasitcal myositis) and by Clostridium perfringens or staphylococcal infections (bacterial myositis). Although myositis is a rather rare disease with an annual incidence of 1:100 000280.000 inhabitants, this illness belonging to the collagenosis group is, on account of the therapeutic consequences (Glucocorticoides and Immunsuppressiva) and the clinically often observed muscle discomfort, of considerable differential-diagnostic meaning. Women are more frequently affected than men, the relation being about 2:1. The age distribution is marked by two maxima, for the juvenile form between the 5th and 15th year and the adult form beyond the 5th decade (2004). The aetiology is unknown. A toxic infectious genesis is discussed among other causes and, in particular with juvenile dermatomyositis, Coxsackie viruses are considered as the cause, an allergic genesis on account of the appearance of a dermatomyositis after taking of antibiotics or sulphonamides and an immunologic genesis on account of the proof of autoantibodies. The illnesses relation with cancer could originate on the base of immunological cross reactions between tumour antigens and skin-muscle antigens or by a myotoxical substance secreted by the tumour tissue (Burmester et al., 2001). A causal connection between malignant and autoimmune disease could be seen in the disappearance or the decline of myositis symptoms after successful treatment of the tumour (in more than 10 % of the observed cases). Various studies show a raised appearance of cancer of the most different kind with patients with diagnosed Myositis (Manchul et al., 1985; Maoz et al., 1998; Zantos et al., 1994).