Flashcards in Chp. 2 Granulomatous Inflammation Deck (11):
Granulomatous inflammation is a ___of chronic inflammation
What is granulomatous inflammation characterized by?
It is characterized by granuloma formation
What is a granuloma?
A granuloma is a collection of EPITHELIOD HYSTIOCYTES
usually surrounded by giant cells and a rim of lymphocytes.
What are epitheliod histiocytes?
These are the hallmark cells of granuloma formation and they are activated macrophages with abundant pink cytoplasm.
What two types are granulomas divided into?
Caseating and non caseating
Describe noncaseating granulomas. What are they commonly due to?
Non caseating granulomas LACK CENTRAL NECROSIS.
They are commonly due to:
Reaction to foreign material
Cat Scratch (Bartonella Henselae)
What is caseating granulomas and what are they commonly due to?
These are granuloma WITH CENTRAL NECROSIS and are characteristic of TB and fungal infections
What are the steps for granuloma formation?
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.
What is a giant cell?
It is a fusion of macrophages (or other cells) with a bunch of nuclei
What cytokine is responsible for inducing CD4+ into Th1 subtype?