Clincial presentation of restrictive lung disease
Cough, SOB and symptoms of the assoicated disease (if present).
Cough, clubbing (but not always) and crackles (CCC).
Restrictive lund disease
/Interstitial lung disease/diffuse parenchymal lung disease.
These disorders are characterised by diffuse and usually chronic involvement of the pulmonary CT, largerly the most peripheral and delicate interstitium in the alveolar walls. With just about all causes initially there is an inflammation within the alveolar walls and spaces. This results in the distortion of the normal alveolar structure and the inflammatory cells release mediators that can injure the parenchymal cells and stimulate fibrosis. Advanced forms may cause gross destruction of the lungs end stage lung or honeycomb lung.
The most common cause of lung restriction
'Pneumonia' in usual interstitial pneumonia
Used broadly to refer to predominantly interstitial inflammation (interstitial pneumonias) of the lung with restriction (but not necessarily infection).
Lung disease due to environmental inhalants. These are often associated with other diseases such as emphysema and mesothelioma due to their common risk factors.
e.g. silicosis, anthracosis, asbestosis etc.
Classification of restrictive lung disease
- Identified cause
- Identified cause
Fibrosing restrictive lung diseases
- Usual interstitial pneumonia (UIPP) (idiopathic pulmonary fibrosis or cryptogenic fibrosing alveolitis)
- Idiopathic non-specific interstitial pneumonia
- Crytogenic organising pneumonia (aka bronchiolitis obliterans organising pneumonia (BOOP))
- Associated with collagen vascular disease
- Drug reactions
- Radiation pneumonitis
Aetiology of UIP
Repeated cycles of alveolitis by an unidentified agent, may be modified by genetic or environmental factors. Predominantly a Th2 response, eosinophils, mast cells, IL-4, IL-13 found in the lesions. TGF-beta1 is released from injured type I alveolar epithelial cells and favours the production of collagen scar tissue in the lung.
Microscopic features of UIP
Cycles of injury and wound healing lead to patchy interstitial fibrosis-fibroblastic foci. Variable states of inflammation and fibrosis- early and late lesions. Lower lobes predominantly show fibrosis. Secondary pulmonary hypertensive changes are often present.
Clinical presentation of UIP
Insidious onset - exertional dyspnoea and dry cough, age 40-70. hypoxia, cyanosis, variably progressive - 3 years or less, some rapid deterioration.
<20% improve with steroids. Lung transplantation required.
Microscopic features of Interstitial non-specific interstitial pneumonia
Not quite characteric features of other interstitial diseases.
Cellular (mild to mdoerate chronic interstitial inflammation, unifrom or patchy) and fibrosing patterns (diffuse or pathy interstitial fibrosis). All lesions are about the same age. Honeycomb areas are rar.e Fibroblasic foci are absent.
Clinical features of interstitial non-specific interstitial pneumonia
Dyspnoea and cough, 46-55 years old.
Those with highly cellular pattern are generally younger and better outcome (than UIP or the fibrosing pattern) - most improve with treatment with steroids.
Cryptogenic organising pneumonia
AKA Bronchiolitis Obliterans Organising Pneumonia.
Characterised by teh polypoid plugs of loose organising CT (all of the same age - known as Masson bodies) within alveolar ducts, alveoli and often bronchioles. Underlying lung architecture is normal. No interstitial fibrosis or honeycomb lung.
Clinical features of Cryptogenic organising pneumonia
Presents in the 50s-60s, men = women, with fever, fatigue, dyspnoea, cough, hypociv, inspiratory crackles, subpleural (therefore peripheral) or peribronchial patchy areas of air space consolidation are seen radiographically.
Spontaneous recovery, oral steroids 6 or so months.
Note: similar picture see in post infection, viral and bacterial pneumonia, inhaled toxins, drugs, collagn vascular disease, graft versus host disease, bone marrow transplant - prognosis same as the underlying disease).
Fibrosing RLD associated with collagen vascular disease
- Systemic lupus erythematosus
- Rheumatoid arthritis (lung pathology seen in 30-40% of pateints)
- Progressive systemic sclerosis (scleroderma)
- Mixed CT disease
Various patterns of lung pathology.
Clinical presentation of fibrosing RLD associated with collagen vascular disease
- Joing pain/swelling
- Rash/skin changes
- Muscular pain/weakness
Induced by organic and inorganic particulates and chemical fumes and vapours. Amount of dust, size (1-5um the worst as they may reach the terminal small airways), shape and buoyance, solubility (small and soluble factors tend to cause acute injury), physiochemical activity (free radical formation in quartz, concomitant tobacco smoking).
Mineral dusts: coal, silica (sandblasters), asbestos (mining milling and fibrication, installation and removal of insulation) these are the more common ones.
Chemical: fumes and vapours
Organic dusts (hypersenssitivity pneumonitis)
- Farmer's lung: mouldy hay - thermophilic actinomycetes
- Bird fanciers lung: proteins from serum, feathers and excrement
- Remember some organic dusts induce asthma (eg wood dust
Fibrosing RLD due to drug reactions
Particularly cytotoxic drugs. Amiodarone.
10-20% of patients 1-6 months after therapy, manifested by fever, dyspnoea, effusion may progress to chronic radiation pnumonitis.
Treat with steroids.
- Hypersensitivity pneumonitis
Disease of unknown aetiology - most likely immune mediated. Characterised by non-caseating granulomas in the lung, hilar lymph nodes +/- skin, eyes. Also seen in spleen and liver and bone marrow at times, mucous membranes and salivary glands.
Clinical presentation of sarcoidosis
Presents with progressive SOB, cough, chest pain, haemoptysis +/- constitutional symptoms (fever, fatigue, weight loss, anorexia, night sweats). Treated with steroids.
Heightened reactivity to an antigen (organic) by the immune system. Inflammation involves the alveoli can progress to fibrosis if the exposure is not removed.
The immune response (immune complex (type III) and T cell mediated delayed hypersensitivity (type IV)).
Important to take a good history, looking for occupational exposures, drugs, pets (birds), work with mould, hay. REMOVE IRRITANT.
Clinical presentation of hypersensitivity pneumonitis
Relapses of SOB, fever, cough, leukocytosis.
May progress to interstitial pneumonia.
Eosinophilic restrictive lung disease
Smoking related restrictive lung disease
- Desquamative interstitial pneumonia
- Respiratory bronchiolitis-associated interstitial lung disease
'other' causes of restrictive lung disease
Pulmonary alveolar proteinosis
Number of different ones. Eosinophils in the alveoli. Respond to steroids.
Desquamative interstitial pneumonia (DIP) and respiratory bronchiolitis-associated interstitial lung disease.
Both show large numbers of smokers' macrophages. The macrophages are within the alveolar spaces in DIP and there is little fibrosis. The macrophages are within first and second order respiratory bronchioles.
DIP can also be seen in non-smokers.
Clinical presentation of DIP and respiratory bronchiolitis-assoicated interstitial lung disease.
Presents in 40-50 year old smokers' with progressive SOB and cough (better prognosis than other interstitial pneumonias).
Steroids used in DIP and stop smoking for both.
Pulmonary alveolar proteinosis
Rare. Accumulation of surfactant in the intra-alveolar and bronchiolar air spaces.
Acquired: 90% immune mediated disorder, antibodies to GM-CSF potentially leads to impared surfactant clearance by alveolar macrophages.
Congential: rare and fatal at 3-6 months of age without a lung transplantor
Secondary: to malignancy, immunodeficiency disorders and other causes.
Clinical presentation of pulmonary alveolar proteinosis
Cough wiht abundant sputum that has chunks of gelitous material.