Hypersensitivity Reactions Flashcards
Type I
IgE
Allergens
Increased eosinophils
Type II
IgG
Insoluble
Immune cytolysis (cell destruction mediated by an antibody that activates complement)
Type III
IgG
Soluble
Immune complex deposition in joints ad kidneys is common
Type IV
Th1 cell mediated
Soluble and Insoluble
Contact dermatitis
allergic rhinitis
Type I
asthma
Type I
systemic anaphylaxis
type I
drug allergies (penicillin)
type II
chronic urticaria (antibody to FceRI
type II
serum sickness
type III
arthus reaction
type III
contact dermatitis
type IV
chronic asthma/chronic allergic rhinitis
type IV
tuberculin reaction
type IV
mast-cell activation
Type I
complement, FcR+ cells (phagocytosis, NK cells)
Type II
Antibody alters signaling
Type II
complement and phagocytes
Type III
macrophage activation
Type IV (Th1 cells)
eosinophil activation
Type IV (Th2 cells)
cytotoxicity
Type IV (CTL)
Delayed-type hypersensitivity
(Type IV) antigen: insect venom, mycobacterial proteins
local skin swelling, erythema, induration, cellular infiltrate, dermatitis
Contact hypersensitivity
(type IV) antigen: haptens, poison ivy (pentadecacatechol, DNFB, metal, chromate
erythema, cellular infiltrate, vesicles, intraepidermal abscesses
gluten-sensitive enteropathy (Celiac’s disease)
(type IV) gliadin
villous atrophy in small bowl and malabsorption
Factors that influence autoimmune diseases
- HLA genotype
- Microbial infections: adjuvant effects and molecular mimicry
- Infection/Inflammation: induction of MHC molecules
- Injury (exposs auto-antigens in immune privileged organs)
- Gender
