Chronic Inflammation

Question 1

What is the dominant cell type in chronic inflammation?

Answer 1

Macrophage

Question 2

Define “chronic inflammation”

Answer 2

Chronic response to injury with associated FIBROSIS

Question 3

In what three ways can chronic inflammation arise?

Answer 3

1. Takes over from acute inflammation
2. Aries de novo, without acute inflammation present
3. Develops alongside acute infection- ongoing bacteria infection UC, Crohn’s for example

Question 4

What does chronic inflammation look like under the microscope?

Answer 4

Mostly macrophages and lymphocytes

Granulation tissue may form

Question 5

When might giant cells be present in chronic inflammation?

Answer 5

When foreign bodies or certain bacteria are present

In granulomatous inflammation

Question 6

What are giant cells?

Answer 6

Fused macrophages

Question 7

What are the three types of giant cell?

Where/when might you see them?

Answer 7

Langhans giant cells - nuclei around periphery of giant cell, often seen in TB

Foreign body giant cells - nuclei are arranged randomly in giant cell, often seen when large, hard to digest foreign body is present

Touton giant cells - nuclei arranged in a ring towards the centre of the cell, form in lesion where there is a high lipid content e.g. fat necrosis, xanthomas

Question 8

Lesions where there is a high fat content, apart from Touton giant cells, will also contain what type of cell?

Answer 8

Foamy macrophages

Question 9

Give some unwanted effects of chronic inflammation

Answer 9

Fibrosis and impaired function - sclerosis, excessive fibrosis
Inappropriate immune response - allergy, hypersensitivity
Tissue destruction, atrophy

Question 10

What is granulomatous inflammation?

Answer 10

A type of chronic inflammation in which granulomas are seen

Granulomas are present in order to help deal with particles that are poorly soluble or difficult to eliminate

Question 11

How do granulomas help to deal with particles?

Answer 11

They form around the particle and wall it off whilst concentrating mononuclear cells within its centre to try and deal with the particle

Question 12

What type of macrophage is commonly found within granulomas?

Answer 12

Epithelioid histiocytes which are modified immobile macrophages

Question 13

What are the two general types that granulomas fall into?

Give examples of each

Answer 13

1. Foreign body granulomas- develop around non-antigenic particles e.g. surgical thread
2. Hypersensitivity (immune) granulomas- around insoluble antigenic particles e.g. TB, Crohn’s, sarcoidosis

Question 14

Give some major clinical examples of chronic inflammation

Answer 14

RA, UC, Crohn’s, chronic cholecystitis, chronic gastritis

Question 15

What is the microscopic appearance of granulomas in TB?

Answer 15

Granulomatous with epithelioid macrophages and Langhan’s giant cells( nuclei around the edge of giant cell)
Lymphocytes, plasma cells, fibroblasts with collagen
Caseous necrosis in the centre (bland pink material on slide)

Question 16

What is the microscopic appearance of granulomas in Sarcoidosis?

Answer 16

Non-caseating epithelioid cell granulomas

Question 17

What is the microscopic appearance of granulomas in the presence of a foreign body?

Answer 17

Granulomas with giant cells present that have nuclei randomly dotted around them
Foreign object particles may be present on slide
Non-necrotic

Question 18

What are rheumatoid nodules and how to they occur?

Answer 18

Localised swelling or lump associated with RA

1. Acute inflammation
2. Granuloma cells
3. Necrotic cells in the core of the nodule

Question 19

What test can be used to distinguish between TB and sarcoidosis?

Answer 19

Acid-fast bacilli - the TB will hold onto the dye