Interstitial lung disease

Question 1

What is the definition of interstitial lung disease?

Answer 1

lung parenchymal disorders with common clinical, radiologic, physiologic and pathologic features; hallmark-involvement of interstitium

Question 2

What is infiltrative lung disease?

Answer 2

infiltration of cellular and non-cellular elements within alveolar septa and alveoli

Question 3

What is diffuse parenchymal lung disease?

Answer 3

DLPD

type of interstitial lung disase

Question 4

What is restrictive lung disease?

Answer 4

characterized by reduced total lung capacity in presence of a normal or reduced expiratory flow rate

Question 5

]What are the chronic interstitial lung disease?

Answer 5

fibrosing lung disorder (pneumoconioses)
granulomatous disorder (sarcoidosis)
idiopathic interstitial pneumonias (IIPs)

Question 6

What is alveolitis?

Answer 6

damage to pneumocytes and endothelial cells

leads to leukocytes releasing cytokines which mediate and stimulate interstitial fibroisis

Question 7

What are the symptoms of interstital fibrosis?

Answer 7

decreased lung compliance and elasticitiy leading to

decreased lung expansion during inspiration

Question 8

What are the clinical and laboratory findings?

Answer 8

Dry cough and dyspnea
late inspiratory crackles, bibasilar (VELCRO CRACKLES)
Cor pulmonale
chest radiography-bilateral reticulonodular infiltrates

Question 9

What is pneumoconioses?

Answer 9

non-neoplastic lung diseases in response to inhalation of mineral dusts inhaled in the workplace

now expanded to include disease induced by organic and inorganic particulate matter

coal dust, silica, asbestos. beryllium 25% cases of chronic interstitial lung disease

Question 10

What is the general pathogenic principles of pneumoconioses?

Answer 10

development

• amount of dust retained in lung parenchyma
• size, shape and buoyancy of particles
• • 1-5 micrometers reach bifurcation of respiratory bronchioles and alveolar duts
• -<0.5 micrometers reach alveoli and phagocytosed by alveolar macrophages
• particle solubility and phsicochemical reactivity
• possible additional effects of other irritants

Question 11

What is coal workers’ pneumoconiasosis?

Answer 11

antithracotic pigment- coal mines, urban centers, tobacco

pulmonary anthracosis

Question 12

What is anthracosis?

Answer 12

asymptomatic

anthracotic pigment in interstitial compartment and lymph nodes

Question 13

Simple coal workers’ pneumoconiosis gross morphology?

Answer 13

fibrous opacities <1cm
upper lobes and upper portions of lower lobes
characterized by coal dust deposits adjacent to respiratory bronchioles

Question 14

What is complicated coal workers’ pneumoconiosis?

Answer 14

progressive massive fibrosis
fibrous opacities >1cm
w/ or w/o central necrosis
massive fibrosis
complication-Cor pulmonale
Caplan syndrome-CWP with rheumatoid nodules in lung
no increased incidence of TB or ccancer

Question 15

What is silicosis?

Answer 15

most comon occupational disease worldwide
crystalline silicon dioxide
quartz activates alveolar macrophages after engulfment ->cytokine release -> fibrogenesis

complications -cor pulmonale; association with Caplan syndrome
increased risk for TB and cancer

Question 16

What are asbestos-related disease appearances?

Answer 16

deposition sites-respiratory bronchioles, alveolar ducts and alveoli

Ferruginous bodies–macropahges and phagocytose asbestos fibers and coat them with ferritin

Question 17

What are the pathogenesis of asbestos-related disease?

Answer 17

benign pleural plaques -- not a prcursor of mesothelioma
diffuse interstitial fibrosis
bronchogenic carcinoma
-additional risk with smoking
-20 yrs after first exposure

Mesothelioma
-no relationship to smoking
-arises from lining mesothelial cells of pleura
-25 to 40 yrs after 1st exposure
no increased risk for TB
complications
-Cor pulmonale
-Caplan syndrome

Question 18

What is berylliosis?

Answer 18

granulomatous inflammation – TB and sarcoidosis

complications -cor pulmonale and lung cancer

Question 19

What is sarcoidosis?

Answer 19

multisystem granulomatous disease of unkonwn etiiology

highest incidence in AA

disorder of immune regulation

Question 20

What are the lab and radiologic findings of sarcoidsosis?

Answer 20

ACE levels
-marker of disease activity and response to steroids
hypercalcemia
polyclonal grammopathy
cutaneous anergy due to consumption fo CD4 Th cells
CXR
-bilateral hilar adenopathy
-reticulonodular shadows in lungs

Question 21

What is HSN pneumonitis?

Answer 21

inhaled antigen producing granulomatous interstitial pneumonitis

Type III hsn rxn

• first exposure – IgG antibodies
• second exposure – antibodies combine with inhaled antigens to form immune complexes
• Chronic exposure –granuloma formation (Type 4 HSN response)

Question 22

What is HSN pneumonitis?

Answer 22

important types

• farmers lung –moldy hay
• -silos fillers disase
• -byssinosis

Question 23

What is idiopathic pulmonary fibrosis?

Answer 23

15% cases of chroonic lung disase
idiopathic interstitial pneumonias
usual interstitial pneumonia ~idiopathic interstitial fibrosis

Question 24

What are the clinical manifestations of idiopathic pulmonary fibrosis?

Answer 24

dyspnea; non-specific constitutional symptoms such as fever, weight loss, fatigue

repeated injury to the lung –> interstitial fibrosis

interstitial fibrosis –> honeycomb lung

Question 25

What is collagen vacular disease causes?

Answer 25

10% of interstitial lung disease
SLE
-interstitial lung disase in 50% of pts
RA
-wide spectrum of pulmonary changes

Systemic sclerosis (scleroderma)
-interstitial fibrosis with pulmonary vascular hypertrophy

Question 26

What is atelectasis?

Answer 26

lung in whole or part is collapsed or without air

-loss of lung volume due to inadequate expansion of airspaces

Question 27

What are the types of atelectiasis?

Answer 27

resorption
compression
loss of surfacant
contraction

Question 28

What is resportion atelectasis?

Answer 28

consequence of complete airway obstruction
obstruction in bronchi, subsegmental bronchi
prevents air from reaching alveoli
resorption of air in distal airspace through pores of kohn
lack of air in distal space
collapse

Question 29

What are teh common causes of obstruction in resorption atelectasis?

Answer 29

mucus/mucopurlent plug following surgery
aspiration of foreing material
bronchial asthma, bronchitis, bronchiectasis
bronchial neoplasm (caveat- total obstruction)

Question 30

What are the clinical findings in resportion atelectasis?

Answer 30

fever and dyspnea (24-36 hours following surgery)
ipsilateral deviation of trachea
ipsilateral diaphragmatic elevation
absent breath sounds and absent vocal vibratory sensation
collapsed lung doesnt expand on inspiration

Question 31

What is compression atelectasis?

Answer 31

air or fluid accumulation in pleural cavity –increased pressure–collapses underlying lung

trachea and mediastinum shift away from atelectatic lung

Question 32

What direction does trachea and mediastinum shift in

• tension pneumothorax
• pleural effusion?

Answer 32

compression atelectasis

shifts away from collapsed lung

Question 33

What is loss of surfacant(neonatal atelactassis)?

Answer 33

lipoportein
-phosphatidylcholine
-phosphatidylglycerol
proteins
--SPA and D innate immunity
--Surfacant protein B and C-- reduction of surface tension at air liquid barrier in alveoli

synthesized by ttype 2 pneumocytes

• synthesis begins by 28th week of gestation
• stored in lamellar boies

Question 34

Neonatal atelactasis histology?

Answer 34

collapsed alveoli are lined by hyaline membranes

Question 35

What are the clinical finidings of neonatal atelactasis?

Answer 35

respiratory distress within a few hours of birth
hypoxemai and respiratory acidosis
ground glass appearance on CXR

Question 36

What are the complications of neonatal atelactasis?

Answer 36

intraventricular hemorrhage
patenet ductus arteriosus
necrotizing enterocolitis
hypoglycemia
O2 therapy-damages to lungs and cataracts

Question 37

What is contraction atelectasis?

Answer 37

fibrotic changes in lung or pleura prevent full expansion (not reversible)

Question 38

What is acute lung injury?

Answer 38

endothelial or epithelial injury initiated by numerous factors
non-heritable and heritable

mediators-cytokines, oxidants, growth factors

manifestations - Pulmonary edema, diffuse alveolar damage (ARDS)

Question 39

What is the cause of pulmonary edema in acute lung injury?

Answer 39

edema to alterations in starling pressure
-microvascular or alveolar injury – increase in capillary permeability
-undetermined origin
therapy and outcome depend on underlying etiology

Question 40

What is acute respiratory distress syndrome?

Answer 40

noncardiogenic pulmonary edema resulting from acute alveolar capillary damage

• -direct lung injury
• -indirect lung injury (systemic disease)

Question 41

What are teh conditions associated with development of majority of ARDS cases?

Answer 41

sepsis
diffuse lung infections
gastric aspiration
physical injury/trauma

Question 42

What are the clinical findings of acute respiratory distress syndrome?

Answer 42

dyspnea
severe hypoxemia not responsive to O2 therapy
respiratory acidosis

Question 43

What is the pathogensis acute respiratory distress syndrome?

Answer 43

acute injury to alveolar epithelial or endothelial cells
alveolar macrophages and other cells release cytokines
-neutrophilic chemotaxis
-transmigration of neutrophils from capillaries into alveoli
-leakage of protein rich exudate forming hyaline membranes
damage to pneumocytes causing surfacant deficiency atelectasis

repair by type 2 pneumocytes
progressive interstitial fibrosis