Muscle expression of PD1 and PD-L1 may predict the severity and outcomes of neuromuscular immune-related adverse events caused by immune checkpoint inhibitor treatment

The muscle pathology of neuromuscular irAEs featured focal necrosis and elevated PD-1 and PD-L1 expression on T lymphocytes and myofibers. PD-1, PD-L1, and PD-L2 expression may be associated with neuromuscular irAE severity and outcomes. Key Points • The muscle pathology of neuromuscular immune-related adverse events includes elevated PD-1 and PD-L1 expression on infiltrating T lymphocytes and muscle fibers. • PD-1, PD-L1, and PD-L2 expression are potential biomarkers for the severity and outcome of neuromuscular immune-related adverse events.