From the Guidelines
Pneumonitis is a potentially life-threatening inflammation of the lung tissue, often caused by immune checkpoint inhibitor therapy, and requires prompt diagnosis and treatment to prevent long-term breathing problems and mortality. According to the most recent and highest quality study 1, pneumonitis is an uncommon but serious toxicity, with a reported incidence of 2.7% in patients treated with anti-PD-1/PD-L1 therapy. The symptoms of pneumonitis can vary, but common presentations include new or worsening cough, shortness of breath, increased oxygen requirement, chest pain, and/or fever 2.
Causes and Risk Factors
The causes of pneumonitis can include exposure to allergens, chemicals, radiation therapy, certain medications, and autoimmune conditions. In the context of immune checkpoint inhibitor therapy, the risk of pneumonitis is higher in patients who receive combination therapy compared to monotherapy, and in patients with non-small cell lung cancer (NSCLC) compared to those with melanoma 1, 3.
Diagnosis and Treatment
Diagnosis of pneumonitis typically involves computed tomography (CT) imaging, which may show focal or diffuse inflammation of the lung parenchyma. Treatment of pneumonitis depends on the severity of the condition, but often includes corticosteroids to reduce inflammation, and may require hospitalization for severe cases 4. 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.
Key Considerations
It is essential to note that pneumonitis can mimic disease progression on imaging and examination, and biopsy may be necessary to confirm the diagnosis. Additionally, patients with preexisting lung diseases, such as chronic obstructive pulmonary disease (COPD) or pulmonary fibrosis, are at higher risk of developing pneumonitis and require close monitoring. Early diagnosis and treatment are critical to preventing long-term breathing problems and reducing mortality associated with pneumonitis.
Some key points to consider in the management of pneumonitis include:
- Removing the triggering substance if possible
- Using corticosteroids to reduce inflammation
- Providing oxygen therapy for severe cases
- Avoiding antibiotics unless a secondary infection develops
- Monitoring patients closely for signs of disease progression or recurrence
- Considering biopsy to confirm the diagnosis in uncertain cases
- Tapering corticosteroids slowly to prevent recrudescence of pneumonitis signs and symptoms.
From the Research
Definition of Pneumonitis
Pneumonitis refers to inflammation of the lungs, which can be caused by various factors such as:
- Inhaled toxicants, including cigarette smoke, wood smoke, and airborne particulates like asbestos and silica 5
- Infections, including bacterial, viral, and fungal infections
- Other factors, such as exposure to certain chemicals or drugs
Types of Pneumonitis
There are different types of pneumonitis, including:
- Atypical pneumonia, which can be caused by certain bacteria, such as Mycoplasma pneumoniae or Chlamydophila pneumoniae 6
- Community-acquired pneumonia (CAP), which can be caused by a variety of bacteria, including Streptococcus pneumoniae 7, 8
- Hypersensitivity pneumonitis, which is caused by an allergic reaction to certain substances, such as mold or dust
Treatment of Pneumonitis
Treatment of pneumonitis depends on the underlying cause and may include: