Background
- the most common IIP
- Epidemiology:
- M>F
- 6th or 7th decade of life, rare < 50
- Chronic, progressive, fibrotic ILD defined by the histologic/radiologic pattern of Usual Interstitial Pneumonia (UIP)
Diagnosis of IPF
- Requires:
- exclusion of other known causes of ILD
- demonstration of UIP pattern on HRCT
- subpleural, basal predominant reticular changes, often heterogenous distribution.
- honeycombing +/- peripheral traction bronchiectasis or bronchiolectasis
- Specific combinations of HRCT pattern and histopathologic patterns in patients subject to tissue biopsy
- Send serologic testing: ANA, RF, anti-CCP, +/- myositis panel +/- Rheum referral.
- MDD (multidisciplinary discussion) to decide whether further diagnosis (bronchoscopy and BAL, surgical lung biopsy, etc) are required
Progressive Pulmonary Fibrosis (PPF)
Treatment of IPF
Acute Exacerbations of IPF
Defined as worsening SOB, hypoxemia with new diffuse bilateral GGO on CT.
Management: - Rule out infection/PE/HF - Consider high dose steroids (1 g/d x 3 --> 1 mg/kg PO daily) and empiric antimicrobials. - Discuss goals of care: 50% in-hospital mortality
Long-Term Management
Non-Targeted
- Smoking cessation
- Oxygen therapy
- PPI
- Pulmonary rehab
- Vaccinations (Pneumococcus, influenza, COVID)
- Advanced care planning
Anti-Fibrotic Medications
Choice is mainly based on side effects and on patient preference.
| Medication | Trials | MOA | Benefits | Adverse Effects |
|---|---|---|---|---|
| Nintendanib | INPULSIS 1/2 | TK inhibitor | Reduces FVC decline, trend to reduced mortality. | Diarrhea, GI upset, transaminitis. |
| Pirfenidone | ASCEND/CAPACITY |
Both are likely equally effective - halves the rate of progression over time.
Immunomodulation in IPF
There is no role for long-term immunosuppression in IPF, given increased mortality (per PANTHER-IPF trial which examined prednisone, azathioprine, and NAC).
Transplant Referral
Consider early referral for IPF and fibrotic NSIP. The criteria are: - FVC < 80% - DLCO < 40% - Needs oxygen - Failed pharmacotherapy
References
- IMR Slides 2021
- Prednisone, Azathioprine, and N-Acetylcysteine for Pulmonary Fibrosis. New England Journal of Medicine. 2012;366(21):1968-1977. doi:10.1056/NEJMoa1113354
- INPULSIS Trials - Wiki Journal Club, Richeldi L, du Bois RM, Raghu G, et al. Efficacy and Safety of Nintedanib in Idiopathic Pulmonary Fibrosis. New England Journal of Medicine. 2014;370(22):2071-2082. doi:10.1056/NEJMoa1402584