Evaluation and treatment of inflammatory myopathies

Abstract

The major types of idiopathic inflammatory myopathy include dermatomyositis (DM), polymyositis (PM), inclusion body myositis (IBM) and immune mediated necrotising myopathy (NM). These myositides appear clinically, histologically and pathogenically distinct. DM, PM and immune mediated NM are responsive to immunosuppressive therapy, in contrast with IBM which is generally refractory to therapy. Greater understanding of the pathogenic bases of these disorders should hopefully lead to better treatment. We need well designed, prospective, double blind, placebo controlled trials in order to determine the best therapeutic options for these different disorders.

Malignancy and myositis: novel autoantibodies and new insights

“…Nevertheless, necrotizing myopathy with pipestem microvascular changes, which is considered an inflammatory myopathy by some authors, has been associated with cancer [19 ]. In this immunomediated myopathy, muscle biopsy specimens characteristically show evidence of massive necrosis of the muscle fibers with almost complete absence of inflammatory infiltrate, which suggests involvement of humoral immunologic mechanisms related with tumor cells.…”

Necrotizing myopathy as a paraneoplastic syndrome associated with renal cell carcinoma

“…2,3,6 No epidemiological data on the relation between CAM and renal cell carcinoma are available. Screening for underlying malignancy in patients with newly diagnosed inflammatory myopathy is mandatory although there is no consensus on how extensive screening for associated cancer should be.…”

“…NAM is clinically resembling polymyositis, but histologically distinct by showing necrotic muscle fibres with minimal or absent inflammatory cell infiltration besides macrophages invading necrotic muscle fibers. 2,3 Case reports and small series of patients reveal a subset of 16% of NAM characterized by anti-signal recognition particle (anti-SRP) antibodies. Although it seems to be an MSA, the link between these antibodies and myositis is not clear yet.…”

Long-term efficacy of intravenously administered immunoglobulin in a case of polymyositis with limited application of steroid therapy

“…Accordingly, a fairly large dose of glucocorticoid has been concomitantly administered in previous studies or reports of IVIG therapy in PM [1][2][3]. From this perspective, our case can be considered exceptional, as we could not administer high doses of glucocorticoid according to the patient's request.…”