Interstitial Lung Disease

Question 1

What is interstitial lung disease?

Answer 1

An umbrella term for diseases which cause scarring of the lungs.
This can occurs via an inflammatory process which is acute and potentially reversible. A fibrotic process which tends to be slower and progressive or an intermediate process which is between the two

Question 2

What is fibrosis?

Answer 2

A repair mechanism gone wrong. It is an aberrant wound healing process which is responsible for prolongation of reparatory process

Question 3

What is interstitial pneumonia and its subtypes?

Answer 3

Inflammation of the interstitial compounant of the lung (chief antigen presentation site, it is the area between the capillary and alveoli)
Divided into usual interstitial pneumonia or non-specific interstitial pneumonia

Question 4

How does enlargement of the interlobular septa present on imaging and what can this be caused by?

Answer 4

• Presents as a reticular pattern due to enlarged septa either because of fibrosis which causes thickening of septa or an increase in lymphatic fluid as lymph vessels flow through the septa.

Question 5

What is idiopathic pulmonary fibrosis

Answer 5

Clinical syndrome and the most common form of pulmonary fibrosis which corresponds to the histological and imaging pattern of usual interstitial pneumonia

Question 6

What is traction bronchiectasis?

Answer 6

• Airway dilatation associated with fibrosis

Question 7

What are the effects of idiopathic pulmonary fibrosis on the lungs?

Answer 7

The lungs become stiffer, smaller (reduced vital capacity) and reduced gas exchange

Question 8

Describe the appearence of idiopathic pulmonary fibrosis on CT and CXR

Answer 8

CT - Reticular pattern at periphery and lower zones of lungs with honeycomb change.
CXR - loss of definition of outlines and hazy

Question 9

What are the factors associated with idiopathic pulmonary fibrosis?

Answer 9

• Smoking,
• Males,
• Heartburn/acid reflux,
• Age (over 75)
• Genetics

Question 10

What are the clinical features of idiopathic pulmonary fibrosis?

Answer 10

Dyspnoea and dry cough which progress over months to years. Clubbing (in around 50%) and diffuse infiltrate on CXR.
Average survival is 2-5 years with variable progression depending on number of acute exacerbations.

Question 11

What is an acute exacerbation of idiopathic pulmonary fibrosis?

Answer 11

• Clear increase in symptoms over the past 30 days.
• New X ray changes in both lungs un absence of infection or other cause.

Question 12

What is the treatment for idiopathic pulmonary fibrosis?

Answer 12

• Anti-fibrotic drugs such as Pirfenidone and nintedanib. These slow deterioration
  not cure.
• Oxygen therapy,
• Pulmonary rehabilitation (limited long term benefit),
• Lung transplant
• Immunosupression is not normally recommended
• Can treat the acid reflux
• Early diagnosis has a better prognosis

Question 13

How is idiopathic interstitial pneumonia classified?

Answer 13

By behaviour. Whether it is reversible or progressive, this then affects the treatment goal. For example if reversible then remove the possible cause (smoking)

Question 14

What is the healing process that leads to fibrosis?

Answer 14

• Injury leads to inflammation which causes a local response and contraction. Instead of regeneration which is the normal process this is when fibrosis occurs/

Question 15

What types of interstitial lung diseases are benefited by treatment with immunosupression?

Answer 15

• Inflammatory diseases such as sarcoidosis.
• Come of the intermediate ILDs if they are on the more inflammatory side

Question 16

What drugs can cause pulmonary fibrosis?

Answer 16

• Amiodarone,
• Nitrofurantoin
• Methotrexate
• Bleomycin