Chp. 2 Granulomatous Inflammation

Question 1

Granulomatous inflammation is a ___of chronic inflammation

Answer 1

Subtype

Question 2

What is granulomatous inflammation characterized by?

Answer 2

It is characterized by granuloma formation

Question 3

What is a granuloma?

Answer 3

A granuloma is a collection of EPITHELIOD HYSTIOCYTES

usually surrounded by giant cells and a rim of lymphocytes.

Question 4

What are epitheliod histiocytes?

Answer 4

These are the hallmark cells of granuloma formation and they are activated macrophages with abundant pink cytoplasm.

Question 5

What two types are granulomas divided into?

Answer 5

Caseating and non caseating

Question 6

Describe noncaseating granulomas. What are they commonly due to?

Answer 6

Non caseating granulomas LACK CENTRAL NECROSIS.

They are commonly due to:
Reaction to foreign material
Sarcoidosis
Be Exposure
Crohns
Cat Scratch (Bartonella Henselae)

Question 7

What is caseating granulomas and what are they commonly due to?

Answer 7

These are granuloma WITH CENTRAL NECROSIS and are characteristic of TB and fungal infections

Question 8

What are the steps for granuloma formation?

Answer 8

1. Macrophages process and present Ag to CD4+ Helper on MHC II. CD4+ binds the Ag
2. Once CD4+ binds the Ag, the Macrophage will release IL-12.
3. IL-12 from macrophage induces CD4+ to differentiate into the Th1 SUBTYPE
4. Th1 cells secrete IFN-y.
5. IFN-y converts macrophages to EPITHELIOID HISTIOCYTES AND GIANT CELLS.

Question 9

What is a giant cell?

Answer 9

It is a fusion of macrophages (or other cells) with a bunch of nuclei

Question 10

What cytokine is responsible for inducing CD4+ into Th1 subtype?

Answer 10

IL-12

Question 11

What cytokine is necessary for the production of epithelioid histiocytes?

Answer 11

IFN-y. Also turns macrophages into giant cells.