Chronic inflammation

Question 1

What is chronic inflammation?

Answer 1

Chronic response to injury with associated fibrosis

Question 2

What can cause chronic inflammation?

Answer 2

Can follow on from acute inflammation
Can arise de Novo
Can be autoimmune
Can be due to low level irritation over time

Question 3

How do you define the type of chronic inflammation?

Answer 3

Look at the cell types that are there. Much more variable than acute inflammation

Question 4

Name a WBC involved in acute and chronic inflammation

Answer 4

Macrophages

Question 5

Name 5 roles of macrophages in chronic inflammation

Answer 5

1) Phagocytose
2) Antigen presenting cells
3) Produce cytokines e.g. IL-1 (produces fever), complement, proteases, clotting factors, over 100 substances that summon other cells
4) Stimulate angiogenesis - important in wound healing
5) Induce fibrosis

Question 6

Presence of lymphocytes indicates likely (virus/bacteria), presence of neutrophils and pus likely (virus/bacteria).

Answer 6

Virus

Bacteria

Question 7

What are the broad roles of B and T lymphocytes

Answer 7

T - Cytotoxic kill (CD8+), helper (CD4+) produce cytokines to direct immune reponse

B - antigen presenting cells, and produce antibodies e.g. differentiate into plasma cells that produce them

Question 8

What are the roles of NK cells? Are they similar to cytotoxic lymphocytes?

Answer 8

Yes type of lymphocyte that can recognise and kill micro-organisms without MHC or antibodies - hence natural killer name

Question 9

Presence of plasma cells indicates infection is ___(chronic/acute)_______ because

Answer 9

Chronic as body now producing antibodies against microorganism

Question 10

When are eosinophils seen in chronic inflammation?

Answer 10

• Large parasites

- Some responses e.g. asthma/some tumours - Hodkins lymphoma

Question 11

What are fibroblasts role in chronic inflammation? How do they migrate to site of injury? What can they differentiate into?

Answer 11

They can chemotaxis to site of injury
They produce connective tissue e.g. collagen, elastin, glycosaminoglycans.
Can differentiate into myofibroblasts which contain actin and can contract - wound healing

Question 12

What are the roles of giant cells in chronic inflammation? Name 3 types

Answer 12

With certain foreign bodies or bacteria, macrophages fuse together to form giant cells (can have 100s of nuclei). Seen in granulomatous infection.

1) Langerhans
2) Foreign body
3) Toutons

Question 13

What are Langerhans cells and when would you see them most commonly?

Answer 13

Type of giant cell where nuclei is arranged around periphery

Often seen in TB

Question 14

What are foreign body giant cells and when would you see them?

Answer 14

Nuclei arranged randomly in the cell
Seen when hard to digest foreign body is present
Foreign body is small gets phagocytosed, if large it sticks to it’s surface

Question 15

What are Touton giant cells and when would you see them?

Answer 15

Nuclei arranged in a ring towards the centre of the cell
Often form in lesions where there is high lipid content e.g. fat necrosis. Seen alongside foam cells. e.g. in atherosclerosis and in xanthomas

Question 16

5 effects of chronic inflammation?

Answer 16

1) Loss of function
2) Rare increase in function
3) Fibrosis
4) Immune response
5) Atrophy

Question 17

What is fibrosis? Why does chronic cholecystitis lead to scarring?

Answer 17

Fibroblasts laying down connective tissue mostly collagen forming a scar.

Repeated acute inflammation by obstruction by gall stones leads to chronic inflammation

Question 18

Give an example of a disease where chronic inflammation impairs function

Answer 18

Loads: e.g. Liver cirrhosis, Chronic inflammatory bowel disease

Question 19

Give an example of a disease where chronic inflammation leads to increased function

Answer 19

Graves disease - leads to hyperthyroidism

Question 20

How is collagen initially helpful in fibrosis?

Answer 20

Walls off area of infection

Attempts to regenerate area of damaged tissue

Question 21

Name some complications of/problems from fibrosis/scarring

Answer 21

1) Can contract and affect function e.g. liver contraction can impair flow of portal blood resulting in ascites
2) Keloid scars
3) Can adhere - e.g. bowel to bladder etc

Question 22

Give an example of an autoimmune disease that involves chronic inflammation

Answer 22

Rheumatoid arthritis - immune system attacks self autoimmune (macrophage/lymphocyte interactions)

Question 23

Give an example where chronic inflammation leads to atrophy?

Answer 23

Gastric mucosa - autoimmune disease, antibodies destroy cells in gastric mucosa that lead to atrophy and scarring

Question 24

How do immune system and chronic inflammation overlap (2)?

Answer 24

Immune disease can cause chronic inflammation

Chronic inflammation can stimulate an immune response

Question 25

What is granulomatous inflammation?

Answer 25

Inflammation with granulomas

Question 26

What is a granuloma?

Answer 26

‘Epithelioid histiocytes’ and Lymphocytes stuck together

Question 27

What are epithelioid histiocytes?

Answer 27

Modified macrophages that are non motile

Question 28

Give an example when you would see caseating granulomas and when would you see non caseating?

Answer 28

Caseating - TB

Non caseating - Sarcoid

Question 29

What is the 4 hallmarks of TB on histology?

Answer 29

A granuloma containing:

1) Langerhans giant cells
2) Caseous centre
3) Epitheliod histiocytes
4) Lymphocytes

Question 30

Name a common organism that causes TB? Is it gram neg or pos

Answer 30

Mycobacterium Tuberculosis

Can appear as both due to its waxy coating so don’t use that to diagnose it.

Question 31

Is TB hard to kill? How does it cause disease?

Answer 31

By persistance and induction of immunity - highly antigenic
Creates chronic inflammation

Hard to kill - doesn’t have toxins or enzymes etc to target

Question 32

Why would a granuloma form? How can they be harmful?

Answer 32

Attempting to digest a particle - surrounds it to then be free or phagocytosed in the centre

They occupy parenchymal space within an organ

Question 33

Definition of an ulcer?

Answer 33

Break down of skin or mucus membrane with loss of surface tissue, disintegration and necrosis of epithelial tissue and often pus.

Question 34

What is the role of giant cells in infection?

Answer 34

Multinucleated giant cells are important mediators of tissue remodeling and repair and are also responsible for removal or sequestration of foreign material, intracellular bacteria and non-phagocytosable pathogens, such as parasites and fungi