Chronic inflammation

Question 1

give features of macrophages

Answer 1

long-lived cells (weeks to months)
phagocytic properties - ingest bacteria and debris
antigen presenting cells to lymphocytes

Question 2

give features of lymphocytes

Answer 2

long-lived (years)
produce cytokines/chemokines (attract other inflammatory cells)
immunological memory for past infections and antigens

Question 3

give a feature of fibroblasts and their role in chronic inflammation

Answer 3

long-lived cells

form collagen for repair

Question 4

give an example of chronic inflammation and its features

Answer 4

TB

• no initial acute inflammation
• mycobacteria ingested by macrophages
• macrophages fail to kill the mycobacteria
• lymphocytes
• fibrosis

Question 5

what type of necrosis is seen with TB?

Answer 5

Caseous

Question 6

what is a granuloma?

Answer 6

An aggregation of epithelioid histiocytes

Question 7

What type of cells are seen in a granuloma

Answer 7

epithelioid histiocytes (activated macrophages resembling epithelial cells)
lymphocytes
multinucleate giant cells (a group of macrophages that have fused to form one cell when trying to ingest particles)
fibroblasts

Question 8

three main cell types in chronic inflammation

Answer 8

lymphocytes
macrophages
plasma cells

Question 9

What are the causes of chronic inflammation?

Answer 9

1. primary
2. transplant rejection
3. progression from acute
4. recurrent episodes of acute inflammation

Question 10

what are examples of primary chronic inflammation?

Answer 10

1. resistance of infective agent to phagocytosis - TB, leprosy
2. endogenous materials - necrotic adipose tissue, bone, uric acid crystals
3. exogenous materials - silica, asbestos, implanted prosthesis
4. autoimmune diseases - Hashimoto’s thyroiditis, rheumatoid arthritis
5. ulcerative colitis
6. primary granulomatous diseases - Crohn’s, sarcoidosis

Question 11

what are the macroscopic appearances of chronic inflammation?

Answer 11

1. chronic ulcer
2. chronic abscess cavity
3. thickening of the wall of a hollow viscus
4. granulomatous inflammation
5. fibrosis

Question 12

exudation of fluid is a prominent feature of chronic inflammation? T or F

Answer 12

False - it is a feature of acute

Question 13

Can tissue necrosis be a prominent feature of chronic inflammation?

Answer 13

Yes - esp in TB and other granulomatous conditions

Question 14

What are the features of repair?

Answer 14

formation of granulation tissue:
1. angiogenesis
2. fibroblast proliferation
3. collagen synthesis
this is regulated by growth factors

Question 15

What are the roles of lymphocytes?

Answer 15

B lymphocytes become plasma cells to produce antibodies

T lymphocytes produce cytokines which recruit and activate other cells

Question 16

give examples of chronic inflammation

Answer 16

chronic peptic ulcer

chronic cholecystitis

Question 17

What are some growth factors in healing and repair?

Answer 17

1. epidermal growth factor - reiterates epithelial cells
2. transforming growth factor beta - stimulates fibroblast proliferation and collagen synthesis
3. platelet derived growth factor - mitogenic and chemotactic for fibroblasts and smooth muscle cells
4. TNF tumour necrosis factor - stimulates angiogenesis

Question 18

what contributes to necrosis?

Answer 18

death of macrophages that releases their lysosomal enzymes

Question 19

Give an example of a cell type in the RES

Answer 19

macrophages

Question 20

Give 4 examples of granulomatous diseases

Answer 20

TB
leprosy
sarcoidosis
Crohn’s disease

Question 21

What may induce granulomatous inflammation?

Answer 21

indigestibility of particulate matter by macrophages

Question 22

What are Langhan’s giant cells?

Answer 22

horseshoe arrangement of peripheral nuclei - TB

Question 23

What do foreign body giant cells look like?

Answer 23

large cells with nuclei randomly scattered throughout their cytoplasm

Question 24

What are touton giant cells?

Answer 24

have a central ring of nuclei with surrounding lipid material
seen when macrophages attempt to digest lipid

Question 25

Does chronic inflammation have a role in carcinogenesis?

Answer 25

Yes - e.g. in ulcerative colitis and tissue response to asbestos

Question 26

What is the role of macrophages in atheroma?

Answer 26

1. phagocytosis of lipids

2. recruit other cells to the site with T cells

Question 27

What is the role of macrophages in MS?

Answer 27

they breakdown myelin