From the Guidelines
Progressing fibrosing interstitial lung disease (PF-ILD) is defined by a decline in forced vital capacity (FVC) of ≥10% or a decline of 5-10% with worsening respiratory symptoms or increased fibrotic changes on CT imaging over a 24-month period, as stated in the most recent guideline 1. This definition is based on the 2023 American College of Rheumatology (ACR)/American College of Chest Physicians (CHEST) guideline for the treatment of interstitial lung disease in people with systemic autoimmune rheumatic diseases.
Key Diagnostic Criteria
The key diagnostic criteria for PF-ILD include:
- A relative decline in FVC of ≥10%
- A decline of 5-10% with worsening respiratory symptoms or increased fibrotic changes on CT imaging over a 24-month period These criteria are useful in assessments for disease progression and are based on the INBUILD trial criteria, as mentioned in the guideline 1.
Disease Progression
Disease progression in PF-ILD can be manifested by:
- Increasing respiratory symptoms
- Worsening pulmonary function test results
- Progressive fibrosis on HRCT
- Acute respiratory decline, as stated in the 2011 ATS/ERS/JRS/ALAT statement 1
Importance of Early Identification
Early identification of progression is crucial as it allows for timely intervention with antifibrotics and consideration for lung transplantation in appropriate candidates.
Treatment Options
Treatment typically involves antifibrotic medications such as nintedanib or pirfenidone, which have been shown to slow disease progression, as mentioned in the guideline 1. These medications work by inhibiting key pathways in the fibrotic process, with nintedanib targeting multiple tyrosine kinases involved in fibroblast proliferation and pirfenidone having anti-inflammatory and antifibrotic properties.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Definition of Progressing Fibrosing Interstitial Lung Disease
Progressing fibrosing interstitial lung disease (PF-ILD) is characterized by:
- A clinical syndrome that shares similar genetics, pathophysiology, and natural history to idiopathic pulmonary fibrosis (IPF) 2
- Inexorable progression of pulmonary fibrosis despite treatment, known as the progressive fibrotic phenotype 3
- A subset of patients with fibrosing interstitial lung diseases (ILDs) who are at risk of developing a progressive phenotype characterized by self-sustaining fibrosis, decline in lung function, worsening quality of life, and early mortality 4
Key Features of PF-ILD
- Accelerated respiratory failure, frequent disease exacerbation, and earlier mortality 5
- Similar mechanisms of self-sustained dysregulated cell repair, fibroblast proliferation, and alveolar dysfunction that can be therapeutically targeted 5
- A diverse group of interstitial lung diseases (ILD) characterized by a similar clinical phenotype 5
Diagnostic Considerations
- Retaining diagnostic scrutiny within the multidisciplinary team is important 3
- A multidomain definition for progressive fibrosis may be suggested 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 6
Treatment Options
- Antifibrotic therapy with nintedanib or pirfenidone slows lung function decline and is the backbone of treatment for IPF with an expanded indication of PF-ILD for nintedanib 2, 5
- Immunosuppression is utilized for some subtypes of PF-ILD, including connective tissue disease ILD and hypersensitivity pneumonitis 5
- Inhaled treprostinil is a novel therapy that improves exercise tolerance in individuals with PF-ILD and concomitant World Health Organization (WHO) group 3 pulmonary hypertension 5
- Lung transplantation is the only curative therapy and can be considered in an appropriate and interested patient 5