What is the recommended evaluation and management approach for chronic interstitial lung disease?

Evaluation and Management of Chronic Interstitial Lung Disease

Initial Diagnostic Evaluation

High-resolution CT (HRCT) chest is the gold standard for diagnosing ILD and must be obtained first to confirm findings and characterize disease pattern. 1, 2

Essential Baseline Testing

• Obtain HRCT chest to identify specific patterns (usual interstitial pneumonia, nonspecific interstitial pneumonia, organizing pneumonia) and assess extent of fibrosis 1, 2
• Perform complete pulmonary function testing including forced vital capacity (FVC), total lung capacity (TLC), and diffusion capacity (DLCO) at baseline 1, 2
• Auscultate for fine "Velcro" crackles on lung examination, which have moderate sensitivity for early ILD detection 3
• Screen for underlying connective tissue disease with rheumatoid factor, anti-CCP antibodies, ANA, anti-Scl-70, anti-Jo-1, and myositis-specific antibodies 4
• Evaluate for environmental/occupational exposures including organic antigens, silica, asbestos, and drug toxicity 4

Avoid Common Pitfalls

• Do not rely on symptom assessment alone - 90% of patients with confirmed ILD on HRCT may not report dyspnea or cough 3
• Bronchoscopy and surgical lung biopsy are not recommended for routine CTD-ILD diagnosis 1
• Chest radiography has low added value compared to HRCT 1

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Risk Stratification and Monitoring Schedule

High-Risk Features for Progression

• Definite fibrosis on CT, subpleural distribution (fibrotic or nonfibrotic subtypes) 2
• Greater extent of abnormalities on imaging 2
• Abnormal or borderline FVC, TLC, or DLCO 2
• Family history of pulmonary fibrosis, older age, smoking history 2

Monitoring Protocol

For newly diagnosed ILD, perform short-term repeat testing to establish progression rate: 1

• PFTs within 3 months of initial evaluation 1, 3
• HRCT within 6 months of initial evaluation 1, 3

Ongoing surveillance depends on disease severity: 1

• Mild ILD (FVC ≥70% and <20% fibrosis on HRCT): PFTs every 6 months for first 1-2 years 1, 3
• Moderate-to-severe ILD or progressive disease: PFTs every 3-6 months 1, 3
• Repeat HRCT in 2-3 years for stable patients, or at 12 months if high-risk features present 2

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Treatment Algorithm by ILD Subtype

Connective Tissue Disease-Associated ILD (CTD-ILD)

Mycophenolate mofetil is the preferred first-line immunosuppressive therapy for all CTD-ILD subtypes, including those with UIP pattern. 1, 2, 4, 5

Alternative first-line immunomodulatory options: 1, 2

• Rituximab (conditionally recommended) 1, 4
• Tocilizumab (conditionally recommended) 1, 6
• Cyclophosphamide (conditionally recommended, typically not combined with other agents) 1, 4, 5
• Azathioprine (conditionally recommended for most SARD-ILD except systemic sclerosis) 1, 4

For systemic sclerosis-ILD specifically:

• Mycophenolate is recommended as first-line therapy 5
• Nintedanib is conditionally recommended as an additional first-line option 1, 6, 5
• Strongly recommend against long-term glucocorticoids in systemic sclerosis-ILD 1

For idiopathic inflammatory myopathy-ILD:

• Calcineurin inhibitors (tacrolimus preferred over cyclosporine) are conditionally recommended as first-line options 1
• JAK inhibitors may be considered for MDA-5-associated ILD but are not preferred first-line therapy 1

Idiopathic Pulmonary Fibrosis (IPF)

For IPF with definite UIP pattern, initiate antifibrotic therapy with nintedanib or pirfenidone, which slow annual FVC decline by 44-57%. 2, 4, 6

• Do not use immunosuppressive therapy for IPF - it is not effective and may be harmful 2, 4
• Pirfenidone and nintedanib have similar efficacy 4

Progressive Pulmonary Fibrosis (PPF)

Identify PPF early using these criteria: 3

• Worsening respiratory symptoms
• ≥10% decline in FVC within past year despite treatment 4
• Radiological evidence of progression on chest CT 3

For CTD-ILD with PPF phenotype:

• Consider adding nintedanib to ongoing immunosuppressive therapy 1, 4, 7
• Evaluate the balance between inflammatory and fibrotic processes to guide treatment decisions 1

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Multidisciplinary Team Approach

Implement a multidisciplinary team (MDT) involving pulmonologists, rheumatologists, and thoracic radiologists for diagnosis and treatment decisions. 1, 3

• MDT integration of HRCT, PFT, and clinical symptoms improves diagnostic accuracy and patient outcomes 1, 3
• Virtual MDT meetings enable clinicians without local access to discuss complex cases 1

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Non-Pharmacological Management

• Counsel on smoking cessation to reduce progression risk 2
• Implement exposure remediation for identified environmental or occupational triggers 2
• Ensure age-appropriate vaccinations 2
• Structured exercise therapy reduces symptoms and improves 6-minute walk test distance 6
• Supplemental oxygen reduces symptoms and improves quality of life in patients who desaturate below 88% on 6-minute walk test 6
• Consider early referral for lung transplant evaluation in patients with advanced disease or progression despite therapy 1, 6

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Special Considerations

Cough Evaluation

Systematically evaluate for alternative causes before attributing cough to ILD itself - gastroesophageal reflux disease (GERD) is a common reversible contributor 4

Disease-Specific Monitoring

For systemic sclerosis: HRCT screening should be performed even in the absence of symptoms due to high ILD prevalence and status as leading cause of death 1

For rheumatoid arthritis: Routine HRCT screening is impractical, but vigilant monitoring using clinical examination for Velcro crackles and risk factor assessment (male gender, smoking, disease duration/severity, high RF or CCP titers) is essential 1