Interstitial Lung Disease Flashcards
What is Interstitial Lung disease?
- Large diverse group of disorders (over 200)
- Usually from injury to the alveolus and surrounding lung parenchyma
- Diseases with many similarities in clinical presentation, radiographic appearance, and physiologic features
- A major national health problem
- Estimated prevalence – 81/100,000 for males and 67/100,000 for females
What is Idiopathic Pulmonary Fibrosis?
• A subset: Idiopathic Pulmonary Fibrosis (IPF)
– Accounts for about 28% of all ILD’s
– 14 to 43 people per 100,000
– 7 to 16 new cases per 100,000 yearly
– 15,000 to 40,000 deaths/year in the U.S.
What are the major categories of Interstitial lung disease?
- Idiopathic Interstitial Pneumonias
- Connective tissue disease/collagen vascular disorders
- Occupational and Environmental exposures – Organic - Inorganic
- Granulomatosis diseases
- Treatment related – Drug Rx - Radiation pneumonitis - Immunosuppression
- Infection
- Interstitial pneumonia with autoimmune features
- Primary (unclassified) ILD – Immunosuppression/transplant
ILD leads to what?
Idiopathic interstitial pneumonia’s are what?
- Idiopathic pulmonary fibrosis – Most common ILD – A diagnosis of exclusion
- Other idiopathic interstital pneumonias
– Non-specific interstitial pneumonia (NSIP)
– Desquamative interstitial pneumonia (DIP)
– Acute interstitial pneumonia/Hamman–Rich syndrome (AIP)
– Respiratory bronchiolitis interstitial lung disease (RBILD)
– Cryptogenic organizing pneumonia/BOOP (COP)
– Lymphocytic interstitial pneumonia (LIP)
– Idiopathic pleuroparenchymal fibroelastosis
– Interstitial pneumonia with autoimmune features
What are the pathologic components of ILD?
What are the stages of idiopathic pulmonary fibrosis?
- Acute injury
- Propagation
- Chronic fibrosis
explain the pathogenesis of Idiopathic Pulmonary Fibrosis?
What is Diffuse paraenchymal lung disease?
–A group of disorders characterized by distinct cellular infiltrates and extracellular matrix deposition within the regions of the lung distal to the terminal bronchiole, i.e., the acinus
Provide an overview of idiopathic pulmonary fibrosis?
Explain the clinical approach to the ILD patient?
- Clinical history
- Clinical examination
- Diagnostic procedures – Blood tests, serologies, etc. – Pulmonary functions test – Chest radiograph – High-resolution computed tomography (HRCT) – Bronchoscopic procedures as indicated
- Endobronchial and transbronchial biopsies
- Bronchoalveolar lavage (BAL) – Surgical biopsy video-assisted thorascopic surgery (VATS) if needed to establish a diagnosis
Explain common changes with interstitial lung disease?
- increased Work of breathing
- decreased FVC
- decreased Lung volumes
- decreased Diffusion capacity
- decreased PO2
- Abnormal CXR/HRCT
Explain Idiopathic Pulmonary Fibrosis?
Idiopathic Pulmonary Fibrosis (IPF) is a restrictive lung disease. It is a specific form of Idiopathic Interstitial Pneumonias (IIP’s). IPF is a chronic, progressive irreversible, fibrosing interstitial lung disease that occurs in adults. Its causes are unknown and its progression unpredictable, but fatal. To date, there is no known cure other than lung transplantation.
What are some risk factors for Interstitial Pulmonary Fibrosis?
- Smoking history especially ≥ 20 packs/year
- Gastroesophageal reflux disease (GERD) a very common finding
- Male predominance
- Age: > 50 years; median age 65-70 years
- Infection
- Genetic factors (familial IPF)
- Environmental exposures
Symptoms of Idiopathic Pulmonary Fibrosis?
- Dyspnea on exertion (progressive)
- Dry cough
- Bibasilar crackles (sounds like velcro being pulled apart)
- Finger clubbing: Occurs in 25-50% of patients
What are some comorbidities associated with Idiopathic Pulmonary fibrosis?
- GERD
- COPD
- Pulmonary hypertension
- Lung cancer
- Obstructive sleep apnea
- Venous thromboembolism
What aspects of the history in idiopathic pulmonary fibrosis are important?
- Past medical history
- Medication/drug history
- Occupational and environmental history
- Smoking history
- Family history
- Pets
- Hobbies
- Travel
usual symptoms and presentation of Interstitial lung disease? what symptoms are absent?
- Dyspnea on exertion – Chronic-slowly progressive
- Cough – Paroxysmal, dry
- Bibasilar crackles (sounds like velcro being pulled apart)
- Hemoptysis – Rare
- Absent – Wheeze – Episodic chest tightness – Respiratory allergies
What are some exceptions to the usual symptoms seen in ILD?
- Acute onset of dyspnea, fever, malaise, headache and fatigue – Hypersensitivity pneumonias – Some drug-induced ILD’s – Infection in immunocompromised host – Toxic gas inhalation
- Pulmonary involvement in collagen vascular disease – Scleroderma – Rheumatoid arthritis – Dermatomyositis
Physical exam findings of ILD?
- Tachypnea
- Inspiratory crackles/rales
- “Clubbed” fingers occurs in 25-50% of IPF cases
- Cyanosis (late)
- Extrapulmonary – Adenopathy – Arthritis – Systemic sclerosis – Rash
- Signs of severe PHT (pulmonary hypertension) – Elevated JVD – Leg edema (late)
What radiographic studies?
- Chest x-ray
- High resolution computed tomography (HRCT)
Radiographic findings seen in CXR with ILD?
Chest x-ray is the initial study When looking at the chest x-ray assess:
• Location of abnormalities:
Upper central
Lower diffuse peripheral
• Pattern Alveolar linear Reticular reticular nodular Honeycombing
High res CT is used how in suspected ILD?
- Standard diagnostic study for all patients suspected to have ILD
- Technique extremely important when doing the study – Thin slices – Prone and supine – Inspiratory and expiration
Patterns of Opactities distribution in ILD?
- Upper – Sarcoidosis, silicosis, pneumoconisosis, langerhans, hypersensitive pneumonitis, reactivation TB, PCP
- Lower – IPF, collagen vascular disease, asbestosis, chronic aspiration
- Peripheral – IPF, CEP, BOOP/COP
- Central – Sarcoid, berylliosis, PCP
Role of Pulmonary function tests in ILD?
- Obtain baseline physiologic function
- Confirm suspected diagnosis
- Evaluate physiologic impairment
- Assess course of disease
- Assess effect of therapy
Assessment of Pulmonary function in ILD?
- Complete PFT – Spirometry (decrease FVC) – Lung volumes (decrease TLC, decrease RV) – DLCO decrease
- Pulse oximetry
- ABG (baseline)
- 6 minute walk test (6MWT)
- Cardiopulmonary exercise test
Explain the changes seen in ABG’s with obstructive and interstitial diseases?
Effect of exercise on ABG’s in interstitial lung disease?
Explain the hypoxemia in shunts?
- Primarily due to abnormal matching of ventilation/perfusion
- “Diffusion Block” due to RBC’s rapid transit through pulmonary capillaries. However, the loss of the capillary bed is a more important cause
- Rarely from shunts
Lab studies in ILD?
CBC
Autoimmune serologies
ESR
ANA titer pattern,
ds DNA
ABG
RA factor
SSA SSB
CK
Serum ACE
Aldolase
Jo1 antibodies
Precipitins to organic antigens
In granulomatous ILD what labs will be elevated?
ESR ANCA ACE
Connective tissue diseases will show what elevated labs in ILD?
ANA RF, anti-CCP Scl-70 antibody Jo-1 antibody
Hypersensitivity Pneumonia will show what with ILD?
Hypersensitivity panel (follow up with exposure history)
IPF shows what on labs?
non-specific
Characteristics of sarcoids, Eosinophilic granulomatosis, Rheumatoid lung disease, SLE, Polymyositis show what on labs?
invasive studies for ILD?
- Bronchoscopy – Endo/transbronchial biopsy – Bronchoalveolar lavage • Not commonly done not that helpful
- Video-assisted thorascopic biopsy (VATS)
Treatment of ILD?
Determined by etiology
Supplemental oxygen as indicated
Pulmonary rehab
Smoking cessation
Pharmacologic interventions
Lung transplant
Pharmocologic agents in ILD?
- Many agents studied – usually dismal results
- Two new agents that slow progression
– Esbriet (Pirfenidone) • MOA: not fully elucidated • Felt to ↓ fibroblast proliferation production and cytokines
– OFEV (Nintedanib) • MOA: a tryosine kinase inhibitor • Shown to inhibit pathways involved in fibrosis
• Unfortunately, neither agent halts disease progression MOA: Mode of Action
Human pentraxin for ILD?
Recombinant Human Pentraxin a possible new treatment for Idiopathic Pulmonary Fibrosis
Currently a phase 2 trial shows promise
Epithelial injury causing abnormal wound repair contributes to the pathogenesis of IPF
Purified serum amyloid P (Pentraxin 2) inhibits monocyte differentiation into profibrotic fibrocytes
Plasma Pentraxin 2 concentrations are reduced in patients with IPF and correlate with disease severity
The hope is that by replacing Pentraxin 2 with Recombinant Human Pentraxin it will result in decreased lung fibrosis
What factors at the time of diagnosis of ILD determine prognosis?
Clinical • Dyspnea
Physiologic • DLCO • 6MWT desaturation • A-a gradient • Pulmonary hypertension • VO2MAX
Radiologic • HRCT pattern (honeycombing) • Extent of fibrosis
Emerging Markers
What indicators for follow up determine the prognosis for ILD?
Physiologic • Forced vital capacity • DLCO • 6MWT desaturation
Clinical: dyspnea
Prognosis of ILD?
- Determined by etiology
- Idiopathic pulmonary fibrosis – Very poor most patients dead 2 ½ to 5 years after diagnosis
– 5-year survival rate between 20% and 40%
– 3 to 9 cases per 100,000 persons/year
– Factors associated with increased survival • Younger age • Female gender • Less functional impairment • Cigarette smoking at time of diagnosis (unexplained)
