From the Guidelines
Diagnosis and Treatment of Interstitial Pneumonitis
Interstitial pneumonitis is a condition characterized by inflammation of the lung interstitium, which can be diagnosed based on clinical and radiographic findings, including symptoms such as shortness of breath, cough, wheezing, chest pain, and reduced exercise tolerance, as well as imaging studies showing cryptogenic organizing pneumonia (COP), nonspecific interstitial pneumonitis (NSIP), hypersensitivity pneumonitis (HP), or usual interstitial pneumonitis (UIP)/pulmonary fibrosis (PF) 1.
Treatment Approach
The treatment approach for interstitial pneumonitis depends on the severity of the condition, which can be graded based on the Common Terminology Criteria for Adverse Events (CTCAE) scale, with grades ranging from 1 (asymptomatic) to 4 (life-threatening) 1.
- For grade 1 pneumonitis, treatment may involve holding immune checkpoint inhibitors (ICIs) and considering pulmonary and infectious disease consultations, with re-imaging at least every 3 weeks to monitor for resolution of radiographic findings 1.
- For grade 2 pneumonitis, treatment typically involves holding ICIs, initiating methylprednisolone at a dose of 1 mg/kg/day, and considering hospitalization and pulmonary consultation for bronchoscopy with bronchoalveolar lavage 1.
- For grade 3 or higher pneumonitis, treatment involves permanently discontinuing ICIs, hospitalizing the patient, and considering intensive care unit (ICU) care, as well as initiating corticosteroids and considering additional immunosuppressive agents such as infliximab and/or cyclophosphamide for recalcitrant disease 1.
Additional Considerations
In addition to corticosteroids and immunosuppressive agents, oxygen therapy and supportive care, such as bronchodilators and pulmonary rehabilitation, may also be necessary to manage symptoms and improve lung function 1. It is also important to monitor patients closely for signs of pneumonitis, particularly those with preexisting lung diseases, and to recognize and treat pneumonitis in a timely manner to prevent poor clinical outcomes 1.
From the Research
Diagnosis of Interstitial Pneumonitis
- The diagnosis of interstitial pneumonitis is based on multiple laboratory findings, radiographic evidence, and high clinical suspicion 2
- Thoracic computed tomography is approximately 91% sensitive and 71% specific for diagnosing subtypes of interstitial lung diseases (ILDs) such as idiopathic pulmonary fibrosis (IPF) 3
- Physiologic assessment provides important prognostic information, with a 5% decline in forced vital capacity (FVC) over 12 months associated with an approximately 2-fold increase in mortality compared with no change in FVC 3
- Radiographic findings such as bilateral infiltrates should be completely resolved after therapy 2
Treatment of Interstitial Pneumonitis
- Antifibrotic therapy with nintedanib or pirfenidone slows annual FVC decline by approximately 44% to 57% in individuals with IPF, scleroderma associated ILD, and in those with progressive pulmonary fibrosis of any cause 3
- Immunomodulatory therapy, such as tocilizumab, rituximab, and mycophenolate mofetil, may slow decline or even improve FVC at 12-month follow-up in patients with connective tissue disease-associated ILD 3
- Steroid therapy with prednisone can improve clinical symptoms and radiographic findings in patients with gemcitabine-induced interstitial pneumonitis 2
- Oxygen therapy can reduce symptoms and improve quality of life in individuals with ILD who desaturate below 88% on a 6-minute walk test 3
- Lung transplantation may improve symptoms and resolve respiratory failure in patients with end-stage ILD, with a median survival of 5.2 to 6.7 years compared with a median survival of less than 2 years in patients with advanced ILD who do not undergo lung transplant 3
Management of Interstitial Pneumonitis
- The management of patients with fibrotic, progressive, and immunosuppressive treatment-refractory interstitial pneumonitis remains uncertain, and further studies are needed to address the role of antifibrotic drugs in this setting 4
- Structured exercise therapy can reduce symptoms and improve 6-minute walk test distance in individuals with dyspnea 3
- Treatment with inhaled treprostinil can improve walking distance and respiratory symptoms in patients with pulmonary hypertension and end-stage fibrotic ILD 3