[Immune checkpoint inhibitor-associated pulmonary adverse events]

Immune checkpoint inhibitors (ICIs), particularly antibodies targeting PD-1, PD-L1, and CTLA-4, have fundamentally transformed the treatment landscape of numerous malignant diseases. By blocking T-cell inhibitory mechanisms, they enable an enhanced immune response against malignancies, but can also trigger immune-related adverse events (irAEs). Pulmonary irAEs - most notably ICI-associated pneumonitis (ICI-P) - occur in up to 20% of treated patients (with study-reported rates ranging from 1-6%) and may progress to respiratory failure. The clinical presentation is characterized by dyspnea, cough, and hypoxemia; radiologically, organizing pneumonia, NSIP pattern, and bronchiolocentric pattern are most commonly observed. Management is severity-dependent and includes treatment interruption, immunosuppression with corticosteroids, and, where necessary, second-line immunosuppressive therapy. The most important differential diagnoses include infection, tumour progression, and radiation pneumonitis.