1 Pathophysiology of ILD

Question 1

What does restrictive lung disease mean?

Answer 1

Decreased compliance

reduced total lung capacity

Question 2

Classification of ILDs

Answer 2

Question 3

Pathology?

Answer 3

Lung responds to damage by attempting to repair:

• inflammation
• fibrosis

of the interstitium (between epithelium and endothelium)

Question 4

Idiopathic Pulmonary Fibrosis

Management compared to non IPF mgmt

Answer 4

Worse prognosis

Mgmt: Antifibrotic drugs (Nintedanib/pirfenidone, NO CORTICOSTEROIDS)
lung transplant, supportive care

Non-IPF: corticosteroids/immunosuppression, lung transplants not necessary or possible

Question 5

ILD relevants from a history

Answer 5

smoking

meds - methotrexate and statins can cause

sarcoidosis/vasculitis

GORD

connective tissue symptoms (ILD is a feature of CTD):

• scleroderma
• polymyositis
• Sicca Syndrome
• Rayaud’s
• alopecia

Question 6

ILD signs found upon examination

Answer 6

>80% have fine respiratory crackles at the lung base

Clubbing

Pulmonary hypertension

extra-pulmonary features of underlying disease

Question 7

Breathing test results in restrictive lung disease (used for monitoring)

Answer 7

FEV1/FEV elevated

reduced TLC, FVC, VC

low DLCO

preserved KCO
(KCO = DLCO/VA (alveolar volume) due to both variables being decreased)

Question 8

There are 3 pillars of care
describe 1. DISEASE SPECIFIC THERAPY

Answer 8

DISEASE SPECIFIC THERAPY

• pharmacology (IPF) targets
  block TGFB activation
  prevent fibrocyte recruitment
  prevent fibroblast activation
  Sucesses: Nintedanib, pirfenidone
• pulmonary rehabilitation
  to interupt cycle of imparied exchange -> decreased activity -> deconditioning etc.
• management of comobidites
  pulmonary hypertension
  CV
  GORD
  Sleep disorders
  depression and anxiety

Question 9

There are 3 pillars of care

describe 2. SYMPTOM BASED MGMT

Answer 9

DYSPNOEA
rehab and education

COUGH
perhaps heightened cough refex or GORD complication - antitussives such as codeine, thalidomide trials

FATIGUE
rehab, oxygen

ANXIETY AND DEPRESSION
rehab, psych support

Question 10

Pirfenidone

Answer 10

Anti-fibrotic (unknown MOA) that inhibits TGF-B induced collagen synthesis

block the mitogenic effect on lung fibroblasts

reduces fibrosis, mortality in animals

side effects: GIT, skin but not much

Question 11

Nintedanib

Answer 11

Intracellular tyrosine kinase inhibitor (also blocks PDGF, FGF and VEGF)

inhibits bleomycin-induced lung fibrosis

Side effects: diarrhoea, <5% discontinued because of this

Question 12

Hypersensitivity pneumonitis - an ILD

Answer 12

An immune reaction to inhaled antigens
T cell mediated response - fibrosis, inflammation and granulatomas

ACUTE: sob, chest pain , fevers, chills, cough, malaise

Tx: remove exposure, CS to immunosuppress

Question 13

Idiopathic Pulmonary Fibrosis - an ILD

presentaiton

pathology

epidemiology

Answer 13

chronic, progressive, fibrosing interstitial pneumonia of unknown cause. most common ILD. no extra-pulmonary features

PRES: progressive SOB, mild cough, decreased exercise tolerance, long asymptomatic period

PATH: inflamm response? may be genetic aberrant healing, honeycomb cysts

EPI:men over 50, 16-70/100,000, 3-5 yr survival, greater mortality than many cancers,