Pulmonary toxicities of immune checkpoint inhibitors

Abstract

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of many malignancies. Toxicities of immunothe­rapy are variable, can involve almost every organ, therefore appropriate diagnosis and management of Immune Related Adverse Events (irAEs) is important. Immune-mediated pneumonitis is an uncommon, but potentially life-threatening toxicity of ICIs. Pre-existing lung disease, a history of lung radiotherapy, age > 70 years and male gender are suggested as the risk factors of pneumonitis. Dyspnoea, dry cough, fever and chest pain are typical symptoms. Diagnostic algorithms recommend radiological investigation with a chest computed tomography scan. Additional diagnostic procedures – such as pulse oximetry, spirometry, measurement of carbon monoxide diffusing capacity, bronchoscopy with BAL may be helpful. The therapeutic approach is determined by the intensity of the symptoms and CT findings. Corticosteroids and antibiotics are the drugs of choice. Hospitalisation is necessary in severe cases, and other forms of immunosuppression (infliximab, mycophenolate mofetil) may be considered. Continuation of immunotherapy can be considered with caution in patients with G1-2 toxicity, when clinical improvement was achieved and steroids were tapered.