Myositis is a group of rare inflammatory diseases of the muscle with distinctive clinical features. When used as cancer treatments, inhibitors of immune checkpoints (ICIs) may boost the immune response against tumor cells, but they can also cause myositis in some patients. This form of myositis is called ICI-myositis and is often associated with heart muscle inflammation (myocarditis). In this report, researchers studied gene expression patterns in muscle biopsies from patients with ICI-myositis and identified three types of inflammatory myositis with distinct clinical features and mRNA expression profiles. They also discovered a common pathway that could be targeted to improve the anti-cancer effects of ICIs.
What is exciting about this article?
This study described three different types of ICI-myositis in cancer patients receiving ICI treatment, namely ICI-dermatomyositis, ICI-MYO1, and ICI-MYO2. Each condition has distinct clinical features and mRNA expression profiles. The authors also reported that genes involved in the IL-6 pathway were over-expressed in all three types of ICI-myositis.
How does this fit into the larger NIAMS portfolio?
Dr. Mammen’s research focuses on human muscle diseases as well as the basic biology of skeletal muscle regeneration. This study identified three different types of ICI-myositis caused by immune checkpoint inhibitor therapy in cancer patients and suggested a potential role of the IL-6 pathway in these ICI-myositis subtypes.
Research reported in this publication was supported by the Intramural Research Program of the NIHʼs National Institute of Arthritis and Musculoskeletal and Skin Diseases.