From the Guidelines
Pneumonitis is defined as focal or diffuse inflammation of the lung parenchyma, typically identified on computed tomography imaging, and can be caused by various factors including immune checkpoint inhibitor therapy, environmental irritants, medication side effects, and autoimmune conditions. The symptoms of pneumonitis may include new or worsening cough, shortness of breath, increased oxygen requirement, chest pain, and/or fever, as reported in a study published in the Journal of Clinical Oncology 1.
Causes and Risk Factors
The causes of pneumonitis can be diverse, ranging from exposure to environmental irritants like mold, bird proteins, or chemicals, to medication side effects from drugs such as chemotherapy agents or antibiotics, and radiation therapy to the chest, as well as autoimmune conditions. A study published in the Journal for ImmunoTherapy of Cancer found that the incidence of pneumonitis in patients treated with immune checkpoint inhibitors can vary, with an overall incidence of 2.7% reported in a meta-analysis of 20 studies with PD-1 inhibition 1.
Diagnosis and Treatment
Diagnosis of pneumonitis often involves computed tomography imaging, and treatment depends on the underlying cause but may include removing the triggering substance, corticosteroids like prednisone, oxygen therapy for severe cases, and sometimes immunosuppressants for autoimmune-related pneumonitis. According to a study published in the Journal of Clinical Oncology, the treatment of patients with symptomatic ICPi pneumonitis with corticosteroids is recommended as an initial treatment, based on several studies that report clinical improvement in > 80% of cases 1.
Management of Immune-Related Adverse Events
For patients with grades 1–2 pneumonitis, management may include drug withdrawal, and for those with pneumonitis grade 3 or higher, hospitalization is typically required, as detailed in a study published in the Journal for ImmunoTherapy of Cancer 1. The study also recommends a minimum 4–6 week taper of corticosteroids to prevent recrudescence of pneumonitis signs and symptoms.
Key Considerations
It is essential to note that pneumonitis can progress to permanent lung scarring (pulmonary fibrosis) if left untreated, emphasizing the importance of prompt medical attention when experiencing respiratory symptoms. The condition differs from pneumonia, which is specifically caused by infection rather than irritation or inflammation from non-infectious sources. A study published in the Journal of Clinical Oncology highlights the importance of being aware of the possibility of immune-related pulmonary reactions, which can mimic disease progression on imaging and examination 1.
From the Research
Definition of Pneumonitis
Pneumonitis refers to inflammation of the lungs, which can be caused by various factors such as infection, exposure to certain chemicals or pollutants, or as a result of an allergic reaction.
Types of Pneumonitis
- Infectious pneumonitis: caused by bacteria, viruses, or fungi
- Chemical pneumonitis: caused by inhalation of toxic substances
- Hypersensitivity pneumonitis: an allergic reaction to certain substances
Community-Acquired Pneumonia
Community-acquired pneumonia (CAP) is a type of pneumonitis that occurs outside of a hospital setting, and can be caused by a variety of bacteria, viruses, and other microorganisms 2, 3, 4.
Treatment of Community-Acquired Pneumonia
The treatment of CAP typically involves the use of antibiotics, such as azithromycin, ceftriaxone, and amoxicillin-clavulanate 5, 2, 3, 4, 6. The choice of antibiotic depends on the severity of the infection, the patient's age and health status, and the suspected cause of the infection.
Antibiotics Used to Treat Pneumonitis
- Azithromycin: a macrolide antibiotic effective against a wide range of bacteria, including those that cause CAP 5, 2, 3, 4
- Ceftriaxone: a third-generation cephalosporin antibiotic effective against a wide range of bacteria, including those that cause CAP 2, 6
- Amoxicillin-clavulanate: a combination antibiotic effective against a wide range of bacteria, including those that cause CAP 4