Restrictive Lung Diseases

Question 1

What is the main physiologic problem in restrictive lung diseases? How does it compare with obstructive?

Answer 1

In restrictive lung diseases there is a problem with filling the lung, as opposed to emptying the lung (obstructive).

Question 2

What lab values classify restrictive lung diseases and what do they mean?

Answer 2

Since there is a problem with filling the lung, TLC (total lung capacity, which is the amount of total air the lungs can take in) will decrease. Similarly, FVC (Forced vital capacity, the amount of air you breathe out after breathing in all the way) will also decrease because you’re taking in less air so you will breathe out less air. FEV (forced expiratory volume, amount of air breathed out in the 1st second after lungs are full) will also decrease due to same reason. FEV1/FVC ratio will be increased to over 80%.

Question 3

How does the FEV1/FVC ratio compare with restrictive lung disease patients? What’s normal?

Answer 3

It will be greater than 80%. Normal FEV1 is 4L, FVC should be about 5, thus the ratio should be 80% or less.

Question 4

Why does FEV1 not decrease in proportion to FVC if both are decreasing?

Answer 4

There is fibrosis associated with restrictive lung diseases so the fibrosis actually helps the elastic recoil in squeezing out the air. However, since there is some sort of restriction to the lungs expanding the lungs CANNOT expand and thus cannot fill, so it will drop more in value relative to FEV1.

Question 5

What is the most common cause of restrictive lung diseases?

Answer 5

Disease of the interstitum, particularly the fibrosis of the interstitum. This first of all prevents efficient gas exchange, and prevents filling of the lung (because its harder to open an fibrosed airway). Can also occur due to restriction of lungs to open mechanically, i.e. obesity.

Question 6

What is Idiopathic Pulmonary Fibrosis (IPF)?

Answer 6

Fibrosis of the lung interstitium. Walls of the alveolar air sacs become extremely thick because of this.

Question 7

Although idiopathic in etiology, what seems to be the pathophys of IPF?

Answer 7

Chronic and cyclical lung injury due to something, that results in damaged pneumocytes. These pneumocytes release TGF-beta in order to heal, which includes fibrosis. Drugs and radiation can also cause this.

Question 8

Which two drugs can cause IPF?

Answer 8

Bleomycin and Amiodarone.

Question 9

Where does the fibrosis begin in IPF? What is the term if the fibrosis spreads diffusely to all over the lung?

Answer 9

In the sub-pleural regions and eventually can spread to the entire lung, which is called “honey comb lung.”

Question 10

How does IPF present?

Answer 10

Shortness of breath that gets progressively worse and cough. CT will reveal fibrosis.

Question 11

How is IPF treated?

Answer 11

Requires lung transplantation.

Question 12

What is “pneumoconiosis?”

Answer 12

Interstitial fibrosis induced by exposure to small fibrogenic particles that are found in various occupation.

Question 13

What is the general theory behind pneumoconiosis?

Answer 13

If the particles were big it would’ve been filtered out by the lung cilia and mucous but if they are small, they will accumulate in areas where only the macrophages can get to, leading to the macrophages reacting via fibrosis.

Question 14

What are the 4 types of pneumoconiosis?

Answer 14

Coal worker’s pneumoconiosis, Silicosis, Berylliosis, Asbestosis.

Question 15

What is “Caplan syndrome?”

Answer 15

Coal worker’s pneumoconiosis + RA = Caplan syndrome.

Question 16

What is “Coal worker’s lung,” how does it come about and how does it present?

Answer 16

Coal workers get exposed to Carbon dust, often in excess. This leads to diffuse fibrosis all over the lung resulting in a shrunk “black lung.”

Question 17

What is “Anthracosis?”

Answer 17

Mild carbon exposure induced blackening of the lung due to macrophages filled with carbon, seen in people living in cities and exposed to pollutants. Also occurs in hilar lymph nodes.

Question 18

What is “Silicosis?” Who gets it?

Answer 18

Sand blasters get it. and this is exposure to silica.

Question 19

What happens when silica enters the macrophages? What is the very significant clinical ramification of this and how does this disease present?

Answer 19

It prevents the phagolysosomes to form and thus it is the ONLY PNEUMOCONIOSIS THAT HAS AN INCREASED RISK OF TB INFECTIONS. Fibrotic nodules in the upper lobes of the lungs (where TB would present).

Question 20

What is Berylliosis, who gets it and how does it present?

Answer 20

This is pneumoconiosis due to beryllium exposure, seen in children and those working in aerospace industry. Presents VERY SIMILAR TO SARCOIDOSIS, because it causes non caseating granulomas in the lung, hilar lymph nodes and systemic organs, just like sarcoidosis would.

Question 21

What is Berylliosis pneumocosis associated with?

Answer 21

Increased risk of lung cancer.

Question 22

What is asbestosis pneumoconiosis?

Answer 22

Seen in construction workers, plummers and shipyard workers.

Question 23

What are the pathological findings of asbestosis?

Answer 23

Fibrosis in the lung or pleura (plaques), cancer of the lung or pleura.

Question 24

What kinds of cancer are asbestos exposure associated with and which is more common?

Answer 24

Associated with lung cancer (most commonly) or cancer of the pleura, aka mesothelioma (less common).

Question 25

How can we confirm the presence of asbestos in patients?

Answer 25

Look for “Asbestos bodies” which are long, thin rod shaped particles with brown beads (which are iron).

Question 26

What is the general pathology of sarcoidosis?

Answer 26

Noncaseating granulomas form in the interstitium of the lung, resulting in restricted filling of the lung. These granulomas are due to some systemic disease and seen in multiple organs, particularly the lung and hilar lymph nodes.

Question 27

Who classically presents with sarcoidosis?

Answer 27

African American women.

Question 28

What is the etiology of sarcoidosis?

Answer 28

Unknown but might be CD4 T cell response to unknown antigen.

Question 29

What is the defining cell of a granuloma?

Answer 29

An epithelioloid histocyte. ALSO will have some giant cells as characteristic cells.

Question 30

What does noncaseating mean in the noncaseating granuloma?

Answer 30

All cells are alive, no necrosis.

Question 31

What is a characteristic cell finding in sarcoidosis?

Answer 31

“Asteroid Bodies” which is a conglomeration of giant cells.

Question 32

Besides the lungs where else can sarcoidosis present?

Answer 32

Uvea (uveitis), skin (cutaneous nodules or erethema nodosum), salivary or lacrimal glands (MIMICS SJOGREN’S SYNDROME!) and any other tissue.

Question 33

Why does sarcoidosis patients also present with hyper Ca?

Answer 33

The noncaseating granulomas has 1 alpha hydroxylase activity and can activate vitamin D. Any disease that have a lot of noncaseating granulomas will have excess 1 alpha hydroxylase activity leading to hyper Ca.

Question 34

How do sarcoidosis pt’s present?

Answer 34

Dyspnea/cough, elevated serum ACE, hypercalcemia. Tx is steroids but can resolve on its own without tx.

Question 35

What is hypersensitivity pneumonitis?

Answer 35

Granulomatous reaction in response to some inhaled organic compound like bird feces (Pigeon Breeder’s lung). Chronic exposure will lead to interstitial fibrosis. Since it is a HS reaction, there will be eosinophils present as well.

Question 36

How are patients presenting with HS pneumonitis?

Answer 36

Fever, cough and dyspnea (initially) hours after exposure, but resolves when the offending substance is removed.