Initial Management of Early Interstitial Lung Disease
For patients with early ILD, obtain high-resolution CT (HRCT) of the chest immediately to confirm diagnosis, characterize the disease pattern, and guide management decisions, as HRCT is approximately 91% sensitive and 71% specific for diagnosing ILD subtypes and plain radiography misses up to 34% of cases. 1, 2, 3
Diagnostic Workup
Exclude Secondary Causes First
Obtain detailed occupational and environmental exposure history including specific job tasks, duration of exposure, use of respiratory protection, and review of material safety data sheets to exclude hypersensitivity pneumonitis, pneumoconiosis (asbestosis, hard metal disease), and chronic beryllium disease 1, 2
Perform serological testing to exclude connective tissue disease as CTD-associated ILD accounts for 25% of all ILD cases and requires different management 1, 3
Document medication history to exclude drug-induced ILD 1
HRCT Pattern Classification
The HRCT pattern determines the diagnostic pathway 1:
UIP pattern (subpleural and basal reticulation, honeycombing, traction bronchiectasis, absence of features suggesting alternative diagnosis): If definite UIP pattern on HRCT in appropriate clinical context, do NOT perform surgical lung biopsy, transbronchial lung biopsy, or lung cryobiopsy 1
Probable UIP, indeterminate for UIP, or alternative diagnosis patterns: Perform cellular analysis of BAL fluid and consider surgical lung biopsy 1
Ground-glass opacities with traction bronchiectasis: Suggests NSIP pattern, common in CTD-ILD 1
Baseline Functional Assessment
Perform pulmonary function tests including FVC and DLCO to establish baseline values, as a 5% decline in FVC over 12 months is associated with approximately 2-fold increase in mortality 1, 3
Measure percutaneous oxygen saturation at end of 6-minute walk test, as oxygen saturation ≤88% during 6MWT at room air predicts increased mortality 1
Assess severity of dyspnea using standardized scales 1
Multidisciplinary Discussion Requirement
Complex cases require multidisciplinary discussion involving pulmonologists, radiologists, and pathologists experienced in ILD to integrate clinical, radiological, and pathological findings for definitive diagnosis 1, 5
- This discussion can be conducted virtually or by telephone when face-to-face meetings are challenging 5
- Share relevant clinical information (patient history, exposures, serological test results) with all parties in advance 5
- Refer complex cases to expert centers or pulmonology departments experienced in ILDs 1
Treatment Initiation Based on Diagnosis
For Idiopathic Pulmonary Fibrosis (UIP Pattern)
Initiate antifibrotic therapy with nintedanib or pirfenidone immediately, as these agents slow annual FVC decline by 44-57% 2, 6, 3
- Do NOT initiate triple therapy with prednisone, azathioprine, and N-acetylcysteine, as this failed to meet efficacy endpoints 1, 7
For CTD-Associated ILD
Mycophenolate is the preferred first-line therapy across all CTD-ILD subtypes 8
- Alternative first-line options include azathioprine (except in systemic sclerosis), rituximab, or cyclophosphamide 8
- For SSc-ILD specifically, tocilizumab and nintedanib are additional first-line options 8
- For idiopathic inflammatory myopathy-ILD, JAK inhibitors and calcineurin inhibitors are additional options 8
For Hypersensitivity Pneumonitis
Immediate and complete avoidance of the causative exposure is the cornerstone of treatment 2, 7
Monitoring Strategy
Serial Pulmonary Function Testing
- Repeat PFTs every 6 months for the first 1-2 years to identify progressive disease 4
- A >5% absolute or 10% relative decrease in FVC over 6 months indicates disease progression requiring treatment adjustment 1
- A >15% decrease in DLCO over 6 months also indicates progression 1
Repeat HRCT Imaging
- For stable disease, repeat HRCT in 2-3 years 2
- For high-risk features or suspected progression, repeat HRCT in 3-6 months to 1 year 4, 8
Assess for Complications
- Screen for pulmonary hypertension with echocardiography, as up to 85% of patients with end-stage fibrotic ILD develop pulmonary hypertension 1, 3
- Pulmonary hypertension develops early in patients with CTD-ILD (can occur as young as 24 years) 9
Prognostic Assessment
Use the GAP (gender, age, physiology) score based on age, sex, FVC, and DLCO to predict survival estimates at 1,2, and 3 years 1
Critical Pitfalls to Avoid
Do not delay treatment while waiting for complete diagnostic workup in patients with progressive symptoms, as early but irreversible lung function loss can occur asymptomatically 1, 4
Do not use long-term glucocorticoids as monotherapy, particularly in SSc-ILD where doses >15mg/day prednisone equivalent increase risk of scleroderma renal crisis 8
Do not assume negative autoantibodies exclude CTD, especially early in disease course 4
Do not rely on chest radiography alone, as it misses up to 34% of ILD cases 2
Do not perform routine genetic testing or telomere length measurement as initial screening 4