Idiopathic Pulmonary Fibrosis Flashcards
What is the pulmonary interstitium?
- Intestinal compartment area between alveolar and capillary endothelial basement membrane
- Expansion of interstitial compartment by inflammation with or without fibrosis
What is interstitial lung disease?
- Anything that affects lung interstitium (lung capillary, epithelium)
- Exposure-related
- IPF-specific anti-fibrotic treatments
- Uncertain aetiology
- Over 5000 cases per year diagnosed in UK
- 2-4 life expectancy after diagnosis
What is the clinical diagnosis for interstitial pulmonary fibrosis?
- Usual interstitial pneumonia (radiologically and histologically)
What are the risk factors for IPF?
- Genetic associations (MUC5B, TOLLIP, Telomerase)
- Cigarette smoking
- Environmental exposures
- Microbial agents
- Gastro-oesophageal reflux (Can be cause or consequence)
What environmental exposures can be a risk factor for IPF?
- Metal and wood dusts:
- Brass, lead, steel, pine
What microbial agents can be risk factors for IPF?
- Herpes viruses- EBV, HHV-7, HHV-8, CMV
- Isolated IPF lungs
What is the clinical presentation of IPF?
- More in males than females
- Incidence increases with age
- Symptoms may develop very gradually over months/years
- At presentation:
- -> Exertional dyspnoea
- -> Dry cough
- -> Digital clubbing (70%)
- -> Diffuse inspiratory crackles (Velcro-type)
What do pulmonary function tests show in IPF?
- Progressive loss of lung volume- restrictive
- Disruption- alveolar-capillary interface–> imparted gas exchange
- Decreased lung compliance- increase work of breathing
- Progressive decline ultimately leading to respiratory failure and death
What is the purpose of a HRCT scan for ILD?
- Essential for its diagnosis
- Radiologist reported sub-pleural reticulation, traction-bronchiectasis and honeycombing consistent with Usual Interstitial Pneumonia
- HRCT Pattern interpreted with clinical context in MDT for diagnosis
What is the histopathology of usual interstitial pneumonia?
- Heterogenous distribution
- Architectural distortion
- Fibrosis with minimal inflammatory infiltrate
- Fibroblastic foci
- Honeycomb cysts
What is the treatment for IPF?
- Pulmonary rehabilitation
- Oxygen therapy
- Symptom control
- Lung transplantation
- -> Late onset is unlikely to be considered for transplant (>65)
What drugs may be used for IPF?
Anti-fibrotics
What is the use of anti-fibrotic for IPF?
- Slow but do not stop the decline in lung function
- 20% will stop due to side effects
Give two examples of anti-fibrotic drugs?
- Pirfenidone
- Nintedanib
What is the dose and side effects for pirfenidone?
- 901 mg (3 tablets) 3x a day
- Side effects: rash, GI and headache
