Flashcards in Type IV Immunopathology Deck (6)
Define type IV immunopathology.
(n.) a form of autoimmunity mediated by T cells; formerly called delayed-type hypersensitivity; does not require antibody or B cells
Explain why a person usually has no observed symptoms when first exposed to a "contact sensitizer" like poison ivy.
Poison ivy irritation is a delayed-type hypersensitivity reaction, so one needs prior exposure to generate memory cells.
Explain the difference between initiation and elicitation.
Initiation creates memory T cells and elicitation excites those cells into action -- generating angry macrophages.
______, and not Th1, would be the predominate cell in a positive PPD at 48 hours.
Macrophages (because Th1 cells can stimulate 1,000 macrophages)
What does abacavir do in 8% of patients?
Changes the HLA B5701 (an MHC I) shape, causing CTLs to attack.