Inflammatory myopathies and overlap syndromes: Update on histological and serological profile

IgG4-Related Sclerosing Cholangitis Involving the Intrahepatic Bile Ducts Diagnosed with Liver Biopsy

“…The patient presented here had unspecified myopathy and noticed a marked improvement related to treatment of IgG4-RD with steroids. It is well known that inflammatory myopathy responsive to steroids can develop in association with autoimmune diseases such as systemic sclerosis, systemic lupus erythematosus, Sjögren's syndrome, and rheumatoid arthritis, a condition termed overlap myositis [ 35 ]. Hence, one may speculate whether there may be a pathophysiologic relation between IgG4-RD and the myopathy in our patient.…”

Comment on: ‘Anti-Ro52 autoantibodies are associated with interstitial lung disease and more severe disease in patients with juvenile myositis’ by Sabbaghet al

“…In particular, JCTM added a great heterogeneity to the study population. In reality, there has been still controversy on considering CTM as a distinct entity or rather a complication related to other connective tissue disease itself 2 3. A recent study3 showed a distinct entity of CTM compared with PM and DM, featuring more extramuscular involvement and more severe infections.…”

The Clinical and Pathological Spectrum of Idiopathic Inflammatory Myopathies : Implications for pathogenesis, classification and diagnosis

“…A muscle biopsy usually confirms the diagnosis, showing inflammatory infiltrates and muscle fiber necrosis [74]. There are however several differences between the disease groups in terms of response to therapy [75], association with MSA and MAA (Table 1), comorbidity [67], and the muscle pathology shows signs of diverging pathogenic processes [5].…”

“…This indicates that clinical or pathological signs need to support the presence of an overlap syndrome. Regardless the chosen distinction, both groups have certainly grown [67], since Bohan and Peter stated diseases, with a known potential to overlap [2,74]. One reason for the increase is the discovery of several MSA and MAA (Table 1), although there is a call for caution in interpretation, given the importance of a valid cut-off, defining a pathological level of antibodies.…”

“…The antisynthetase syndrome [65] and mixed connective tissue disease (MCTD) [66] are early examples of diseases, where autoantibodies have helped to define clinical syndromes, including myositis. Subsequently others have followed [67], and will be discussed in the next section.…”