From the Guidelines
The diagnosis of Usual Interstitial Pneumonia (UIP) requires a multidisciplinary approach combining clinical features, high-resolution CT scan findings, and sometimes lung biopsy, as outlined in the 2022 ATS/ERS/JRS/ALAT clinical practice guideline 1. The diagnosis of UIP is based on the presence of a specific pattern of lung fibrosis characterized by patchy involvement of the lung parenchyma with areas of fibrosis alternating with normal lung tissue. This pattern is the hallmark pathological finding in idiopathic pulmonary fibrosis (IPF), though it can also be seen in other conditions such as connective tissue diseases, drug reactions, and chronic hypersensitivity pneumonitis.
Key Diagnostic Features
- High-resolution CT scan findings showing peripheral, basal predominant reticular abnormalities with honeycombing and minimal ground-glass opacities
- Clinical features such as progressive worsening of dyspnea and lung function
- Sometimes, lung biopsy is necessary to confirm the diagnosis
Treatment Options
- Antifibrotic medications such as pirfenidone (801 mg three times daily) or nintedanib (150 mg twice daily) are recommended to slow disease progression 1
- Supportive care is essential, including:
- Supplemental oxygen when hypoxemia is present
- Pulmonary rehabilitation
- Vaccination against respiratory infections
- Management of comorbidities like gastroesophageal reflux
- For eligible patients with advanced disease, lung transplantation may be considered
Pathogenesis and Prognosis
- The pathogenesis involves recurrent alveolar epithelial cell injury leading to aberrant wound healing and progressive fibrosis, with genetic factors, environmental exposures, and aging all contributing to disease development
- Prognosis is generally poor with a median survival of 3-5 years from diagnosis if untreated, though antifibrotic therapy can improve outcomes, as noted in the 2022 guideline 1
From the FDA Drug Label
The efficacy of pirfenidone was evaluated in patients with IPF in three phase 3, randomized, double-blind, placebo-controlled, multicenter trials (Studies 1,2, and 3). Study 1 was a 52-week trial comparing pirfenidone 2,403 mg/day (n=278) versus placebo (n=277) in patients with IPF Studies 1,2 and 3 enrolled adult patients who had a clinical and radiographic diagnosis of IPF (with or without accompanying surgical lung biopsy), without evidence or suspicion of an alternative diagnosis for interstitial lung disease
The diagnosis of Usual Interstitial Pneumonia (UIP), also known as Idiopathic Pulmonary Fibrosis (IPF), is based on a combination of clinical and radiographic findings, including:
- High-resolution computed tomography (HRCT) scans
- Surgical lung biopsy (in some cases) The treatment of UIP/IPF with pirfenidone involves administering the drug at a dose of 2,403 mg/day, divided into three doses taken with food, for a minimum of 72 weeks 2.
From the Research
Diagnosis of Usual Interstitial Pneumonia (UIP)
- The diagnosis of UIP can be established by surgical lung biopsy or by high-resolution thin-section computed tomographic (CT) scans, provided the radiographic features are classical 3
- Definitive diagnosis requires the exclusion of known causes of pulmonary fibrosis and identification of the UIP pattern of disease either on high-resolution computed tomography (HRCT) scan of the chest or on surgical lung biopsy 4
- Multidisciplinary discussion involving pulmonologists, radiologists, and pathologists with expertise in the diagnosis of IPF and other forms of interstitial lung disease is recommended and often required 4
Treatment of Usual Interstitial Pneumonia (UIP)
- Pirfenidone treatment can slow decline in forced vital capacity (FVC) in idiopathic pulmonary fibrosis (IPF) and has been shown to be effective in patients with UIP, with or without pleuroparenchymal fibroelastosis-like lesions or nonspecific interstitial pneumonia 5, 6
- Pirfenidone lessens the annual reduction of pulmonary volume (FVC) and of the distance walked in 6 minutes by about 30%, with corresponding improvement of progression-free survival, but without any significant lessening of overall mortality 6
- Lung transplantation is the only current treatment that enables long-term survival 6, 3
- Treatment strategies for UIP should be based on multidisciplinary evaluation, integrating all available information, with a final 'working diagnosis' made for treatment purposes 7