Peds Allergies Flashcards
step 1
antigen presenting cells
what are the antigen presenting cells
Dendritic cell
Landerhan cells
macrophages
who do the antigen presenting cells present to
t cells
where are immature dendritic cells found
lungs, skin, intestine
what do dendritic cells do
Actively phagocytize antigens
Cells migrate to area lymph nodes
Antigens are fully processed & converted –>
Causing T-cells to proliferate and differentiate
what is step 2
Th2 (for atopic pts)
TH1 (non atopic)
what happens for Th2
secretion of cytokines (favor IgE mediated response)
secrete interleukins:
Switch immunoglobulin isotypes to IgE
Enhance IgE synthesis
Differentiate and develop eosinophils (from stem cells)
Contribute to mast cell development
TH1 response
secrete cytokines and active IgG responses
step 3
IgE
where are IgE dervied from
plasma cells (activated lymphocytes)
what is acute allergic responses dependent on
IgE and its ability to bind to the allergen (then it causes the intracellular cascade)
step 4
eosinophilia
what do eosinophils do
help defend against parasites
accumulate where allergic rxns take place
what do eosinophils contain
intracellular granules that are sources of inflammation:
Damage epithelial cells (e.g. atopic dermatitis)
Induce airway hyper-responsiveness
Degranulate basophils and mast cells
where are mast cells derived from
bone marrow, immature go through blood and go to specific tissue where they mature (stay in tissue and near vessels-do NOT circulate)
