Diagnostik und Therapie der Myositis

Abstract

The identification of differentiating antibodies and the use of more subtle imaging procedures and diagnostic histopathological procedures have allowed for idiopathic inflammatory myopathies (IIM) to be classified more accurately in the past few years. In addition to polymyositis, dermatomyositis and inclusion body myositis (IBM), the antisynthetase syndrome has been identified. Causative factors like myotoxic substances should be looked for especially in cases of necrotising myositis. Malignant diseases should always be ruled out in myositis patients, especially when anti-TIF1 gamma or anti-NXP-2 antibodies have been identified. As myositis may be a forerunner of a tumour, follow-up investigations are essentiell in this setting. Glucocorticoids and immunoglobulins still constitute the standard treatment for this condition. Rituximab (RTX) is a milestone in the treatment of severe IIM. Although the RIM study missed its primary endpoint, it has shown obvious responses in the majority of patients, as has also been demonstrated in several case reports and case series with large numbers of patients. Many patients need just one course of treatment (RTX). A number of patients receive several courses at large intervals and tolerate the treatment well. Subgroups will be defined even more specifically in the future, and it will be possible to differentiate responders from non-responders in advance. The detection of the first antibody and preliminary data on bimagrumab lead to the emergence of promising new treatment options for IBM. The management of infections, dysphagia, severe organ involvement and multimorbidity in an aging patient population continues to be a challenge in this context.