Interstitial Lung Disease

Question 1

interstitial lung disease

Answer 1

aka diffuse parenchymal lung disease

disease of the alveolar wall, including the interstitium, the potential space between the basement membranes of the alveolar epithelium and the capillary endothelium

may also involve the alvolar space and small airways

Question 2

four categories of ILDs

Answer 2

ILDs of known cause or association

idiopathic interstitial pneumonias

granulomatous ILDs

other (rare) DPLDs

Question 3

interstitial lung diseases with a known cause

Answer 3

pneumoconiosis - exposure to inorganic dusts

hypersensitivity pneumonitis - immunologic response to inhaled organic dusts

reactions to chemicals, drugs, radiation, and toxic gases

those associated with connective tissue disease

Question 4

proposed pathogenesis of ILD

Answer 4

age related susceptible lung

wound clot

aberrant epithelial cell activation

fibroblast focus

epithelial-mesenchymal transition

hypercoagulable milieu

exaggerated ECM accumulation

progressive lung remodeling

honeycomb changes

Question 5

categories of idiopathic interstitial pneumonias

Answer 5

chronic fibrosing IIP

smoking-related IIP

acute/subacute IIP

Question 6

chornic fibrosing IIPs

Answer 6

idiopathic pulmonary fibrosis (IPF)

idiopathic nonspecific interstitial pneumonia (NSIP)

Question 7

smoking-related IIPs

Answer 7

respiratory bronchiolitis - interstitial lung disease (RB-ILD)

desquamative interstitial pneumonia (DIP)

Question 8

acute/subacute IIPs

Answer 8

cryptogenic organizing pneumonia (COP

acute interstitial pneumonia (AIP)

Question 9

symptoms of ILD

Answer 9

exertional dyspnea, usually insiduous

cough, usually non-productive

Question 10

physical findings of ILD

Answer 10

fine, end-inspiratory crackles (“Velcro rales)

digital clubbing (IPF)

cyanosis

signs of cor pulmonale increased P2, RV lift, R-sided S3, JVD, edema (advanced disease)

Question 11

findings on ILD chest x-ray

Answer 11

10% are normal at initial presentation

reticular, nodular, or reticulo-nodular interstitial pattern

diffuse and patchy alveolar pattern

Question 12

reticular pattern

Answer 12

indicative of IPF

Question 13

nodular pattern

Answer 13

indicative of sarcoidosis

Question 14

alveolar pattern

Answer 14

much more homogeneous and confluent

Question 15

common abnormalities of IL on HRCT

Answer 15

reticular opacities

nodular opacities

ground glass opacities

traction bronchiectasis

honeycomb cysts

Question 16

traction bronchiectasis

Answer 16

bronchi are bigger than expected for specific lung sizes due to airways being pulled open

Question 17

reticular opacities

Answer 17

indicative of scleroderma

Question 18

nodular opacities

Answer 18

suggestive of sarcoidosis

Question 19

ground glass opacities

Answer 19

suggests hypersensitivity pneumonitis

Question 20

honeycomb cysts

Answer 20

suggestive of IPF

Question 21

pulmonary function test results for ILD

Answer 21

restrictive defect most common

decreased lung volumes (TLC, FRC, RV)

normal or elevated FEV1/FVC

decreased lung compliance

reduced diffusion capacity

mixed restrictive and obstructive defect possible

Question 22

arterial blood gas for ILD

Answer 22

increased A-a gradient, decreased PaO2

Question 23

pneumoconiosis

Answer 23

ILD caused by inorganic dusts

silica -> silicosis

coal dust -> coal workers pneumoconiosis

asbestos -> asbestosis

hard metal alloys -> giant cell pneumonitis

berylium 0> berylliosis

Question 24

hypersensitivity pneumonitis (HP)

Answer 24

ILD caused by inhalation of organic dusts

moldy hay -> farmer’s lung

bird proteins -> bird fancier’s disease

Question 25

drugs that can cause ILD

Answer 25

chemotherapeutic agents (bleomycin, busulfan, methotrexate)

antibiotics (nitrofurantoin)

drug-induced lupus (hydralazine, procainamide)

miscellaneous (gold salts, amiodarone)

Question 26

connective tissue diseases that can lead to ILD

Answer 26

rheumatoid arthritis

systemic lupus erythematosis

progressive systemic sclerosis (scleroderma)

Sjogren’s syndrome

polymyositis and dermatomyositis

mixed connective tissue disease

anylosing spondylitis

Question 27

idiopathic pulmonary fibrosis (IPF)

Answer 27

unknown cause, limited to the lungs

more common in men, usually for people > 60 yrs old

risk factors include smoking and dust exposure

histologial pattern of UIP

no effective therapy

median survival 3-3.5 years

Question 28

histologic findings for IPF

Answer 28

heterogeneit, alternating zones of interstitial fibrosis, inflammation, honeycombing, and normal lung

patchy thickening of alveolar septa

fibroblastic foci with scant inflammation

honeycomb lung, broad bands of firosis with little inflammation, no remaining alveoli - end stage disease

Question 29

idiopathic nonspecific interstitial pneumonia (NSIP)

Answer 29

associated with auto-immune phenomena

more common in women

smoking not a risk factor

usually diagnosed in middle age

may respond to steroids and other immunosuppressive treatments

prognosis better than IPF

Question 30

histologic findings in NSIP

Answer 30

cellular and fibrotic variations

a lot more inflammatory cells in cellular

less so in fibrotic

don’t see honeycomb cysts

Question 31

sarcoidosis

Answer 31

multi-system disease of unknown cause

commonly affects young and middle aged adults, more common in African Americans

most common presentatin is ILD, thoracic lymph node enlargement

other organs also involved (skin, eyes, nose, liver, heart, CNS)

non-caseating epithelioid granulomas

responsive to steroids

Question 32

Which diseases can be diagnosed with a bronchoscopic transbronchial biopsy?

Answer 32

granulomatous processes

neoplasm

infection

most ILDs require surgical lung biopsy

Question 33

treatment of ILD

Answer 33

removal of offending agent, if identified

corticosteroids for sarcoidosis (not useful for IPF)

cytotoxic/immunosuppressive agents

antioxidants

investigational anti-fibrotic agents

supplemental oxygen

influenza and pneumococcal vaccines

pulmonary rehabilitation

lung transplantation

Question 34

cytotoxic/immunosuppresive agents for ILD

Answer 34

azathioprine

cyclophosphamide

mycophenolate mofetil

tacrolimus

Question 35

perfenidone

Answer 35

investigational anti-fibrotic agent