Hypersensitivities Flashcards
(27 cards)
T/F all forms of hypersensitivities require prior exposure to the antigen
TTTRRRUUUEEE!!!!!
what are the 4 types of sensativities
I - (immediate) IgE
II - (antibody mediated) IgM / IgG
III - (immune complex) IgM / IgG
IV - T cell
what is the initial exposure with Type I
- allergen enters body
- T cells turn into Th2 subset
- B-cells make IgE
What is the sensitization with Type I
-IgE bind with mast cells
2nd exposure will activate mast cells
What is the Allergic Reaction with Type I
- allergen binds to IgE on mast cell
released: histamine, Prostaglandins, leukotrienes (PRO-INFLAMMATORY)
what are the 2 types of reactions with Type I
- Systemic anaphylaxis
2. Localized anaphylaxis
is systemic anaphylaxis injected or ingested
injected (ie. bee sting)
-results in shock
is locaized anaphylaxis injected or ingested
ingested or inhaled
what are the symptoms of an upper respiratory Type I reaction
- itchy eyes, congestion, sneezing
- due to: pollen, pet dander, dust mite feces
what are the symptoms of a lower respiratory Type I reaction
asthma
tx- Epi-pen, albuterol
what are the symptoms of a GI Type I reaction
Hives
-due to: peanuts, milk, egg etc.
what is the long term treatment for Type I
- desensitize
- convert IgE to IgG
where does the antibody of a Type II attach
surface of cells or the ECM
what are the means of destruction with a Type II
- ADCC
2. Complement
what does ADCC stand for
Antibody- dependent cell-mediated cytotoxicity
how does ADCC kill tagged tissue
WBCs bind to Fc region of IgG or IgM and kill the cell
what Ab are good at fixing complement in Type II
IgM and IgG
What is an example of a Type II
hemolytic disease in new born (dad is RH+, mom is RH-, baby is RH+, moms immune system attacks 2nd babies immune system)
where does the Ab-Ag complex go in Type III
accumulates and deposits in tissue and cause inflammation
where do Ab-Ag complex in Type III like to deposit
vascular walls, joints, kidneys
how does Ab-Ag complex in Type III cause a reaction
phagocytes try to eat the Ab-Ag complex and release inflammatory chemistry which destroy surrounding tisse
What are some examples of Type III
Vasculitis, Rheumatoid Arthritis (can be III or IV)
what is happening in a Type IV
inappropriate or excessive immune response from T cells (against self or exogenous)
what T cells mediates “Delayed” Type IV
CD4 Helper T cells (Th1 and Th17 subsets)
