granulomatous inflammation

Question 1

subtype

Answer 1

subtype of chronic inflammation

Question 2

characterized

Answer 2

characterized by granuloma, collection of epithelioid histiocytes

usually surrounded by giant cells and a rim of lymphocytes

Question 3

two subtypes

Answer 3

noncaseating granulomas and caseating granulomas

Question 4

noncaseating granulomas

Answer 4

lack central necrosis

common etiologies include reaction to foreign material, sarcoidosis, beryllium exposure, crohn disease, and cat scratch disease

Question 5

caseating granulomas

Answer 5

exhibit central necrosis and are characteristic of tuberculosis and fungal infections

Question 6

3 steps

Answer 6

macrophages process and present Ag to helper T cells

interaction leads macrophages to secrete IL-12, induces T cell differentiation (cytotoxic T cells)

Th1 cells secrete IFN-gamma, converts macrophages to epithelioid histiocytes and giant cells