Prevalence and Prognostic Impact of Progressive Pulmonary Fibrosis

Progressive pulmonary fibrosis (PPF) is a clinical phenotype observed in various interstitial lung diseases (ILDs) other than idiopathic pulmonary fibrosis. It is characterized by worsening fibrosis on high-resolution computed tomography, a progressive decline in lung function, and deteriorating respiratory symptoms. Despite shared pathophysiological mechanisms, the rate of disease progression and clinical outcomes vary significantly among the different subtypes of PPF. Key predictors of poor prognosis include advanced age, male sex, rapid lung function decline, hypoxemia, pulmonary hypertension, and radiologic features such as a usual interstitial pneumonia pattern and traction bronchiectasis. Genetic factors, particularly telomere shortening and mutations in telomere-related genes, have emerged as important determinants of prognosis and therapeutic response. Acute exacerbations of PPF are associated with a poor shortterm prognosis and represent a major cause of morbidity and mortality in PPF. The introduction of antifibrotic therapies has significantly altered the management of PPF by slowing the decline in lung function. However, their impact on long-term survival remains under investigation.