Myopathy in systemic sclerosis

Purpose of review: Systemic sclerosis associated myopathy (SSc-AM) is a complex, heterogenous disease that is associated with poor outcomes. SSc-AM lacks a clear definition, and continues to be poorly recognized. The purpose of this review is to provide a contemporary overview of the clinical, serological and pathophysiologic findings in SSc-AM to guide optimal recognition and management of this challenging disease manifestation.

Recent findings: There have been several advances in diagnostic techniques to facilitate characterization of SSc-AM, including muscle MRI, in which findings were correlated to distinct histopathologic categories of muscle involvement in SSc, histopathologic findings of prominent fibrosis or inflammation on biopsy, and the identification of novel autoantibodies associated with SSc-AM, which may be associated with distinct clinical phenotypes. In one of the largest studies to date, 17% of a well phenotyped SSc cohort were found to have myopathy, which was an independent risk of death, even after adjusting for potential confounders, further highlighting the importance of timely recognistion and management of SSc-AM.

Summary: There is increasing recognition of the importance of SSc-AM. Novel diagnostic tools provide the opportunity for more detailed insights into pathophysiologic mechanisms, which may facilitate the development of a rigorous consensus definition of SSc-AM.