L10: Hypersensitivity Flashcards
what antibodies are involved in type I hypersensitivity ?
IgE
What are the effector cells in type I hypersensitivity?
mast cells , eosinophils , basophils
what happens when someone is exposed to an alergen for the first time >?
1.) alergen stimulates formation of antibodies
2.)binding of IgE antibodies to mast cells by Fc portion
what happens when a person is exposed to an allergen they’ve already been exposed too?
allergen binds to IgE antibodies on mast cells causing degranulation and release of mediators like histamine
what are primary mediators in type I hypersensitivity and when are they released?
primary mediators are mediators already present in mast cells and basophil granules and they are released in the immediate phase of type I hypersensitivity
what are secondary mediators and when are they released?
secondary mediators are ones that are formed after stimulation by mast cells and basophils / other leukocytes .
they are slow acting
they are released as part of the late phase of type I hypersensitivity
when can you see the late phase of type 1 hypersensitivity ?
after 6 hours
what stimulates the formation of secondary mediators ( type I)?
mast cells and basophils / other leukocytes
increased production of which intelukin can cause elevated levels of IgE?
IL-4
target tissue in type I hs usually have high number of _____
helper T-cells (Th-2)
what antibodies mediate type II hs?
IgM and IgG
What types of hs involve the activation of classical pathway ?
types II and III
Blood transfusions can result in which type of hs?
Type II
type III hypersensitivity is mediated by which antibody>?
IgG
which HS is characterized by deposition of immune complex at localized site ?
Type III
