From the Guidelines
Interstitial lung abnormalities (ILAs) are defined as incidental radiographic findings on chest imaging that affect the lung parenchyma, specifically the interstitium, and include ground-glass opacities, reticular patterns, traction bronchiectasis, honeycombing, and non-emphysematous cysts. These abnormalities are typically detected incidentally on CT scans performed for other reasons and represent early or mild forms of interstitial lung disease that haven't yet progressed to cause significant symptoms or functional impairment. The clinical significance of ILAs lies in their potential to progress to clinically significant interstitial lung disease over time, with some studies showing associations with increased mortality, reduced lung function, and increased respiratory symptoms 1. Key characteristics of ILAs include:
- Incidental detection on chest imaging, particularly CT scans
- Involvement of the lung interstitium
- Presence of specific radiographic patterns such as ground-glass opacities and reticular patterns
- Potential for progression to clinically significant interstitial lung disease
- Association with increased mortality, reduced lung function, and increased respiratory symptoms in some cases While the exact definition and clinical implications of ILAs are still being researched, the current understanding is that ILAs represent a spectrum of early or mild interstitial lung disease that requires monitoring and potentially intervention to prevent progression. According to recent guidelines, individuals with systemic autoimmune rheumatic diseases, such as rheumatoid arthritis and systemic sclerosis, are at higher risk of developing ILD and should be screened and monitored accordingly 1. Overall, the definition and clinical significance of ILAs are complex and multifaceted, and require a comprehensive approach to diagnosis, monitoring, and management to optimize patient outcomes.
From the Research
Definition of Interstitial Lung Abnormalities
- Interstitial lung diseases (ILDs) are a complex group of conditions that cause inflammation and scarring of the lung interstitium 2.
- ILDs are characterized by inflammation or fibrosis within the interstitial space, resulting in impaired gas exchange, breathlessness, diminished exercise tolerance, and decreased quality of life 3.
- The term "interstitial lung abnormalities" refers to a heterogeneous and complex group of conditions characterized by inflammation, fibrosis, or both, in the interstitium of the lungs 4.
Key Features of Interstitial Lung Diseases
- Over 200 interstitial lung diseases are recognized, ranging from ultra-rare to relatively common 3.
- Most ILDs are characterized by inflammation or fibrosis within the interstitial space, resulting in impaired gas exchange 3.
- ILDs can be caused by factors such as genetic predispositions, environmental exposures, underlying autoimmune diseases, or the use of certain medications 4.
Diagnosis and Management of Interstitial Lung Diseases
- A multidisciplinary approach to diagnosis is the gold standard, involving key history and examination features, blood panel, pulmonary function tests, high-resolution computed tomography imaging, and when required, bronchoalveolar lavage and lung biopsy results 2.
- Advances in disease-modifying anti-fibrotic medications, such as nintedanib and pirfenidone, continue to shape the future management of interstitial lung disease 2.
- Immunomodulatory therapies are largely successful in the management of ILDs and can be safely managed with the application of specific protocols, precautions, and monitoring 5.