Immune checkpoint inhibitor-related myositis and myocarditis with multiple myositis-specific/−associated antibodies

In recent years, immune checkpoint inhibitors (ICI) have become the standard treatments for various cancers. These drugs are monoclonal antibodies targeting molecules such as cytotoxic T lymphocyte antigen 4(CTLA-4), programmed death 1 (PD-1), and PD-1 ligand (PD-L1). ICI activate the immune system to eliminate malignancies. ICIs can cause organ-specific immune-related adverse events (irAEs) [1]. ICI-related myositis/myocarditis accounts for 0.15–0.24% of ICI-administrated patients [2]. The details of the pathogenesis of ICI-related myositis/myocarditis are still unclear, but it has been postulated that there are two distinct forms of the disease: a cellular immune-mediated form and a humoral immune-mediated form [3].