Interstitial Lung Dz Flashcards
Objectives
1
Q
Interstitial Lung Dz
A
- A broad category of chronic lung diseases that includes >130 disorders characterized by scarring of the lungs and/or inflammation of the lungs.
- Cancer and infectious causes must be ruled out.
- Broadly classified into Idiopathic Pulmonary Pneumonias and Non-Idiopathic Interstitial Pulmonary Fibrosis.
2
Q
ILD Pathophys
A
- Common pathophysiology is thought to have begun with an acute injury to the lung parenchyma leading to chronic interstitial inflammation. Then fibroblast activation and proliferation results in pulmonary fibrosis and tissue destruction.
- Usually insidious in onset but can be acute and rapidly progressive.
3
Q
ILD clinical presentation
A
- Most common is dyspnea on exertion (DOE).
- Chronic non-productive cough.
- Clubbing of the nails.
- Often found as abnormal CXR on routine exam.
- Hemoptysis.
4
Q
ILD Hx
A
Very important in order to appropriately diagnose the problem.
- Thorough occupational history (e.g. asbestos, silica, heavy metals, moldy foliage, farming,) environmental (pigeon breeding, hot tub, ventilation systems/ humidifiers).
- Drug history. WHAT HAVE YOU TAKEN? amiodarone that we give for afib, commonly causes interstitial disease
- Smoking history.
- Family history.
- Risk factors for immunosuppression.
Pay close attention to the onset and duration of symptoms, the rate of disease progression and associated symptoms
5
Q
ILD PE
A
- May be very limited or normal
- Possible wheezing
- Digital clubbing
- Possible S3 gallop which represents cor pulmonale
- Pedal edema
- Possible lymphadenopathy in sarcoidosis
- Cutaneous or articular findings in rheumatologic diseases
6
Q
ILD Non-invasive Testing
A
- Lab tests (findings usually non-specific)
- Routine: CBC with diff, ESR, CMP, U/A, ABG
- Disease specific:
- ANA for SLE
- rheumatoid factor for RA
- antineutrophil cytoplasmic antibodies for Wegener’s granulomatosis
- anti-basement membrane antibodies for Goodpasture’s syndrome
- CXR
- Reticular and nodular opacities are the hallmark, normal findings in 10% of patients. Other diseases have specific CXR characteristics
- CT Scan
- Linear reticular opacities are the most common finding. Disease specific characteristics have allowed for radiographic diagnosis in >50% of cases.
- Pulmonary function tests (PFTs)
- Typical finding is of a restrictive pattern with decreased diffusion capacity.
- Your DLCO will be reduced in patients
7
Q
Invasive Testing
A
- Bronchoscopy with BAL and TBBx
- Bronchoalveolar lavage (BAL)
- Not required for diagnosis but can help to rule out other diseases.
- Transbronchial biopsy (TBBx)
- Often of limited value because inadequate sampling
- Can help to rule out other diseases.
- Bronchoalveolar lavage (BAL)
- Many patients require open or thoracoscopic lung biopsy
8
Q
Histopathology
A
- Histopathology is widely varied.
- Sent to speciality lung referral center for bx
- Interpretation is difficult and there can be disagreement between pathologists.
9
Q
ILD Classification: Idiopathic Pulmonary Pneumonias
A
- Idiopathic pulmonary fibrosis (IPF)
- Nonspecific interstitial pneumonia (NSIP)
- Desquamative interstitial pneumonia (DIP)
- Respiratory bronchiolitis interstitial lung disease (RBILD)
- Acute interstitial pneumonia (AIP)Cryptogenic organizing pneumonia
- Lymphoid interstitial pneumonia
10
Q
ILD Classification: Non-Idiopathic Interstitial Pulmonary Fibrosis
A
- Associated with environmental or occupational exposure
- Associated with Rheumatologic/ connective tissue disorder
- Associated with drug exposure
- Sarcoidosis and other granulomatous lung diseases
- Associated with other systemic diseases
- inherited lung dz
11
Q
Idiopathic Pulmonary Pneumonias
A
- A group of disorders that have a common clinical, radiographic and physiologic characteristics with no defined cause.
- Known causes of interstitial lung disease must be ruled out.
- Characterized by varying degrees of fibrosis and/or inflammation that effects the interstitium to a greater degree than the airways or alveoli.
12
Q
Idiopathic Pulmonary Pneumonias: Idiopathic pulmonary fibrosis (IPF)
A
- 50-60% of IPPs
- CT- great extent of honeycombing of lung and no ground glass appearance;
- Lung biopsy shows histologic pattern called usual interstitial pneumonia (UIP)
- Progressive lung dysfunction with fatal outcome despite aggressive treatment with steroids and immunosuppressive therapy (azathioprine)
- Lung transplant has best survival data.
- Median survival 3-5 years from dx with or without treatment
13
Q
Idiopathic Pulmonary Pneumonias: Nonspecific interstitial pneumonia (NSIP)
A
- Often associated with or looks like collagen vascular diseases or hypersensitivity pneumonitis
- CT shows predominance of ground glass attenuation
- Prognosis generally better than IPF
- Prognosis: NSIP > IPF
- CT: ground class NSIP vs no ground glass and honey combing IPF
14
Q
Idiopathic Pulmonary Pneumonias: Respiratory bronchiolitis interstitial lung disease (RBILD)
A
- Almost always associated with chronic and current smoking
- Usually occurs in 4th -5th decade
- PFTs – varying degrees of airway obstruction with only mildly decrease or normal total lung capacity and decreased DLCO
- BAL- numerous brown pigmented alveolar macrophages. Think smoker’s fingers are brown
- Histology- pigmented alveolar macrophages with glassy eosinophilic cytoplasm and granular pigmentation within respiratory bronchioles. Honeycombing NOT present
- Prognosis is good with smoking cessation. Must stop smoking.
*occasionally needs steroids, short burst, short duration, secondary to EXTREME sensitivity to cigarette smoke
15
Q
Idiopathic Pulmonary Pneumonias: Lymphoid interstitial pneumonia
A
- Very rare
- Look for concurrent collagen vascular disease
- Variable prognosis with steroid treatment
16
Q
Idiopathic Pulmonary Pneumonias: Desquamative interstitial pneumonia (DIP)
A
- Very rare
- Most pts are smokers
- Outcome generally good with stopping smoking and oral steroids.
- 70% survive 10 years
17
Q
Idiopathic Pulmonary Pneumonias: Acute interstitial pneumonia (AIP)
A
- Seen in otherwise healthy persons immediately after apparent viral illness.
- Rare but serious disease characterized by diffuse alveolar damage with subsequent fibrosis.
- 70% fatal in 3 months.
- Also called Hamman-Rich syndrome.
- Management is largely supportive.
- Histologically indistinguishable from ARDS.
18
Q
Idiopathic Pulmonary Pneumonias: Cryptogenic organizing pneumonia
A
*Previously referred to as a Bronchiolitis Obliterans Organizing Pneumonia (BOOP)
- Commonly manifest as a flu-like illness with non-productive cough followed by exertional dyspnea.
- Most are current or past smokers
- CT shows airspace consolidation (organizing pneumonoia) and lower lung zone predominance often with ground glass appearance
- BAL: non –specific
- Histology—excessive proliferation of granulation tissue within small airways and chronic inflammation in the
- Most recover completely with oral corticosteroids but may relapse after cessation and require long term steroids
