- Pulmonary fibrosis is a chronic and progressive lung disease characterized by the scarring (fibrosis) of lung tissue, leading to a gradual decline in respiratory function. The condition involves the thickening and stiffening of the alveolar walls due to the accumulation of fibrotic tissue, which hampers the lungs’ ability to efficiently exchange oxygen and carbon dioxide. As fibrosis progresses, patients experience increasing shortness of breath, particularly during physical activity, along with symptoms such as chronic dry cough, fatigue, unexplained weight loss, and chest discomfort.
- The term “pulmonary fibrosis” encompasses a variety of interstitial lung diseases (ILDs), and in many cases, the cause remains idiopathic, leading to a diagnosis of idiopathic pulmonary fibrosis (IPF)—a particularly aggressive and fatal form of the disease. Other forms of pulmonary fibrosis can be triggered by environmental exposures (such as asbestos, silica dust, or bird droppings), radiation therapy, certain medications (e.g., some chemotherapy agents and antibiotics), autoimmune diseases (like rheumatoid arthritis or systemic sclerosis), and genetic predispositions.
- At the cellular level, pulmonary fibrosis is marked by chronic injury to the alveolar epithelium, abnormal wound-healing responses, and excessive activation of fibroblasts and myofibroblasts, which produce large amounts of collagen and extracellular matrix components. This leads to architectural remodeling of the lung parenchyma and the irreversible loss of functional alveolar spaces. In idiopathic forms, repeated micro-injuries to the lung are thought to trigger abnormal repair processes rather than inflammation, setting it apart from more classic inflammatory lung conditions.
- Diagnosis of pulmonary fibrosis typically involves a combination of clinical history, pulmonary function tests (PFTs), imaging studies such as high-resolution computed tomography (HRCT), and sometimes lung biopsy. HRCT often reveals hallmark features like honeycombing, reticular patterns, and ground-glass opacities, depending on the stage and type of fibrosis. Pulmonary function tests usually show a restrictive ventilatory defect, characterized by reduced lung volumes and a decline in diffusing capacity for carbon monoxide (DLCO).
- Treatment options for pulmonary fibrosis are limited and mainly aim to slow disease progression, alleviate symptoms, and improve quality of life. Antifibrotic drugs such as pirfenidone and nintedanib have been approved for IPF and have shown efficacy in reducing the rate of lung function decline. Supportive therapies include oxygen supplementation, pulmonary rehabilitation, and vaccinations to prevent respiratory infections. In advanced cases, lung transplantation may be the only viable option, particularly for younger patients with severe functional impairment and no significant comorbidities.
- The prognosis for pulmonary fibrosis varies depending on the underlying cause, severity, and response to treatment, but idiopathic pulmonary fibrosis often follows a relentlessly progressive course, with a median survival time of 3 to 5 years after diagnosis. Ongoing research seeks to better understand the molecular mechanisms behind fibrosis and to develop more targeted and effective therapies.
