Lecture 16 3/25/24 Flashcards
What is hypersensitivity?
excessive response to innocuous antigens
What are examples of type 1 hypersensitivity?
-allergy
-atopy
-anaphylaxis
What are the mediators of type 1 hypersensitivity?
-IgE
-eosinophils
-mast cells
-histamine
What is an example of type 2 hypersensitivity?
immune-mediated hemolytic anemia
What are the mediators of type 2 hypersensitivity?
-IgG
-IgM
-binding to blood
What is an example of type 3 hypersensitivity?
glomerulonephritis
What are the mediators of type 3 hypersensitivity?
-antigen-antibody complexes
What is an example of type 4 hypersensitivity?
TB test (delayed response)
What are the mediators of type 4 hypersensitivity?
-cell-mediated
-T lymphocytes
-macrophages
What are the characteristics of a flea/food allergy?
-common skin problem in small animal
-IgE mediated response
-epidermal hyperplasia with compact hyperkeratosis seen on histopath.
-eosinophils numerous in dermis
What are the characteristics of canine atopic dermatitis?
-elevated IgE in response to environmental antigens
-clinical signs usually begin before 3 years of age
-dogs are pruritic, but eosinophils are not found in skin lesions
What are the characteristics of anaphylaxis?
-severe, generalized, life-threatening hypersensitivity
-mediated by mast cells releasing histamine and leukotrienes
-edema and smooth muscle contraction occur
-vasodilation results in hypotension and shock
-drugs are most common cause
What are the characteristics of autoimmune disease?
-immune reaction to self-antigens
-antigens will never be eliminated or cleared
What is pemphigus foliaceus?
antibodies against desmoglein result in loss of cell cohesion and intraepidermal vesicles
What are the characteristics of exocrine pancreatic atrophy?
-T lymphocytes cause apoptosis of exocrine pancreatic cells
-endocrine pancreas is not affected
-german shepherds and rough collies are predisposed
