S3 Chronic Inflammation

Question 1

What are the features of chronic inflammation?

Answer 1

Prolonged inflammation with associated repair

• delayed onset
• variable duration (days to years)
• variable appearances
• limits damage, initiates repair
• can cause debilitating symptoms

Question 2

How can chronic inflammation arise?

Answer 2

• can take over from acute inflammation (if resolution isn’t possible with acute inflammation)
• develops alongside acute inflammation (severe/persistent irritation)
• arises ‘de novo’ (no acute inflammation before e.g. in autoimmune conditions)

Question 3

What cell types are involved in chronic inflammation?

Answer 3

• macrophages
• lymphocytes
• plasma cells
• eosinophils
• basophils
• giant cells
• fibroblasts/myofibroblasts

Question 4

What is the name for a macrophage in circulation?

Answer 4

Monocyte

Question 5

What is another name for macrophages?

Answer 5

Histiocyte

Question 6

What is the shape/structure of macrophages like?

Answer 6

Shape is inconsistent based on what they are engulfing

• nuclei look a bit like ‘slippers’
• large cells
• have an abundant foamy cytoplasm (phagolysosomes)

Question 7

What is the function of macrophages?

Answer 7

• phagocytosis - removal of pathogen/necrosis/debris and antigen presentation to immune system
• synthesise and release inflammatory mediators which control and regulate the inflammatory response

Question 8

What is the shape/structure of lymphocytes?

Answer 8

• small cells (slightly larger than RBCs)
• have a spherical nucleus
• have a thing rim of cytoplasm around the nucleus

Question 9

What is the function of lymphocytes?

Answer 9

• T cells - helper (assist other inflammatory cells) and killer (destroy pathogens)
• B cells - mature into plasma cells, produce antibodies, neutralise pathogens

Question 10

What is the structure/shape of plasma cells?

Answer 10

• eccentric nucleus - ‘clock face’ chromatin

* have a peri-nuclear clearing - a paler area around the nucleus (where Golgi bodies are present)

Question 11

What is the function of plasma cells?

Answer 11

They are fully differentiated B lymphocytes that produce antibodies

Question 12

What is the structure of an eosinophil?

Answer 12

• bilobed nucleus

* granular cytoplasm that stains red

Question 13

What is the function of eosinophils?

Answer 13

• release mediators (that result in an allergic reaction)

* involved in hypersensitivity reactions and parasitic infections

Question 14

What is the role of fibroblasts and myofibroblasts?

Answer 14

Involved in regeneration and repair

Question 15

What is the structure of giant cells?

Answer 15

• multinucleate cells

* result from the fusion of many macrophages

Question 16

What are the 3 types of giant cells? How are their nuclei arranged?

Answer 16

1. Foreign body giant cell - random
2. Langhans giant cell - ‘horse shoe’ shape
3. Touton giant cell - arranged in circle towards centre

Question 17

In what disease are langhans giant cells most commonly seen in?

Answer 17

Tuberculosis

Question 18

In what type of necrosis are touton giant cells most commonly seen in?

Answer 18

Fat necrosis

Question 19

Give an example of conditions that you see more 
1. Plasma cells
2. Lymphocytes 
3. Macrophages 
In

Answer 19

1. Rheumatoid arthritis
2. Chronic gastritis
3. Leishmaniasis (protozoan infection)

Question 20

What does chronic inflammation result in?

Answer 20

• fibrosis
• impaired function
• atrophy
• stimulation of immune response

Question 21

How do gall stones result in gall bladder fibrosis?

Answer 21

1. Repeated obstruction of bile duct by gall stones
2. Repeated bouts of acute inflammation which leads to chronic inflammation
3. Fibrosis of the gall bladder walls occurs (looks thickened and pale)

Question 22

Compare Crohn’s disease and ulcerative colitis.

Answer 22

Crohn’s - affects all of GI tract, has discontinuous patches of inflammation (skin lesions), inflammation affects full thickness of the bowel wall (trasnmural), granulamata can be present, less likely to have rectal bleeding

Colitis - affects only the large bowel, has continuous inflammation, inflammation affects only the superficial bowel wall (mucosa and submucosa), no granulomata present, more likely to have rectal bleeding

Question 23

What can cause liver damage?

Answer 23

• alcohol
• hepatitis
• drugs and toxins
• fatty liver disease

Question 24

What is granulomatous infection?

Answer 24

Type of chronic inflammation that involves formations of granulomas

Question 25

What is a granuloma?

Answer 25

A collection of epithelioid histiocytes (macrophages that look like epithelial cells) with lymphocytes surrounding these

Question 26

What type of other cell can you get in granulomas?

Answer 26

Giant cells

Question 27

What can cause granulomatous infection?

Answer 27

• foreign body reaction
• infections e.g. Mycobacterium tuberculosis or Mycobacterium leprae
• idiopathic (spontaneous)

Question 28

Why do Mycobacterium result in granulomatous infection?

Answer 28

Because they are difficult to destroy due to a thick cell wall and mycolic acids on the cell wall

Question 29

What sort of necrosis occurs in a mycobacterium granuloma?

Answer 29

Caseous necrosis

Question 30

What are two example of a idiopathic granulomatous inflammation?

Answer 30

Crohn’s disease - it is a non-caseating granulomata in the GI tract

Sarcoidosis - non-caseating granulomata in the lymph nodes, lungs and skin