From the Guidelines
Interstitial fibrosis is a chronic and progressive condition characterized by the excessive deposition of collagen and other extracellular matrix components in the interstitial spaces of organs, leading to irreversible scarring and organ dysfunction. This condition develops as a result of chronic inflammation or injury, where normal tissue repair mechanisms become dysregulated, leading to progressive scarring that replaces functional tissue. In the lungs, interstitial fibrosis causes thickening of the alveolar walls, reducing oxygen exchange and causing shortness of breath, as noted in the American Thoracic Society and European Respiratory Society guidelines 1. The development of interstitial fibrosis involves activated fibroblasts and myofibroblasts that produce excessive collagen in response to inflammatory mediators and growth factors like TGF-β. Some key points to consider in the management of interstitial fibrosis include:
- The use of antifibrotic medications like pirfenidone or nintedanib for pulmonary fibrosis, as recommended in the latest guidelines 1
- Addressing the underlying cause of the condition
- Reducing inflammation with corticosteroids or immunosuppressants
- Considering organ transplantation in severe cases It is essential to note that the treatment of interstitial fibrosis is often challenging, and the condition can lead to significant morbidity and mortality if left untreated or poorly managed, highlighting the need for early intervention and a comprehensive treatment approach, as emphasized in the recent clinical practice guideline 1.
From the Research
Definition and Characteristics of Interstitial Fibrosis
- Interstitial fibrosis refers to the scarring of the lung tissue, which can lead to progressive dyspnea and respiratory failure 2
- It is a characteristic feature of fibrosing interstitial lung diseases, which are a heterogeneous group of parenchymal lung disorders 3
- Interstitial lung diseases can be caused by various factors, including idiopathic pulmonary fibrosis, hypersensitivity pneumonitis, and connective tissue disease 2
Pathophysiology and Progression
- The pathophysiology of interstitial fibrosis involves the infiltration of the interstitial space with derangement of the normal capillary-alveolar anatomy 3
- The disease can progress over time, leading to a decline in lung function and increased mortality 4, 2
- A 5% decline in forced vital capacity (FVC) over 12 months is associated with an approximately 2-fold increase in mortality compared with no change in FVC 2
Treatment and Management
- Antifibrotic therapy with nintedanib or pirfenidone can slow annual FVC decline by approximately 44% to 57% in individuals with idiopathic pulmonary fibrosis, scleroderma-associated interstitial lung disease, and progressive pulmonary fibrosis of any cause 2
- 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 interstitial lung disease 2
- Structured exercise therapy, oxygen therapy, and lung transplant may also be effective in managing interstitial lung disease 2
Ongoing Research and Future Directions
- Several clinical trials are ongoing to assess the safety and efficacy of nintedanib and pirfenidone in non-idiopathic pulmonary fibrosis progressive fibrotic interstitial lung diseases 5, 6
- New therapeutic approaches, including novel antifibrotic agents and non-pharmacological treatments, are being investigated to improve symptom control and quality of life in patients with interstitial lung disease 4, 6