IMMUNITY DISEASE I TERMS Flashcards
the immune system protects against exogenous substances
immunity
damage normal host tissue
autoimmune reactions
blood transfusions
react to homologous antigens
endogenous antigens
autoimmunity
mediated by cells and proteins that are always present and have evolved to specifically recognize microbes and protect individuals against infections
innate immunity
block entry of microbes
epithelial barriers
mainly neutrophils and macrophages
phagocytic leukocytes
provide early protection against many viruses and intracellular bacteria
NK cells
normally silent and is activated by the presence of infection, mechanisms are stimulated by the microbes capable of recognizing microbial and non microbial substances
adaptive (acquired) immunity
mediated by soluble proteins called antibodies produced by B-lymphocytes
humoral
mediated by T lymphocytes
cell mediated
name this hypersensitivity reaction?
mediated by IgE antibodies bound to mast cells and basophils in response to a particular antigen like allergens
these release mediators and pro inflammatory cytokines which recruit inflammatory cells
type I anaphylactic (immediate)
name this cytokine
this stimulates B cells specific for the allergen to undergo heavy chain class switch IgG to IgE and to secrete this immunoglobulin
IL-4
name this cytokine
activates eosinophils
IL-5
name this cytokine
acts on epithelial cells and increases mucus secretion
IL-13
most abundant mediator generated by cyclo-oxygenase pathway
-bronchospasm, increased mucus secretion like asthma
PGD2
most potent vasoactive and spasmogenic agents
several thousand times more active than histamine on a molar basis
LTC4 and LTD4
highly chemotactic for neutrophils, eosinophils and monocytes
LTB4
activation of mast cells results in synthesis and secretion
important in late phase reaction
cytokines
what is this reaction
may result in systemic anaphylaxis; bee venom, drugs/medications
level of sensitization
pruritis, urticaria, erythema
bronchoconstriction, laryngeal edema, obstruction
systemic reaction
what is this reaction
limited exposure; skin, GI, lung
urticaria, allergic rhinitis, asthma
local reaction
what is this hypersensitivity reaction?
caused by antibodies directed against target antigens on cell surface or other tissue components
type II antibody mediated
cells are coated with autoantibodies with or without complement proteins
receptors for Fc portion of IgG and for C3 breakdown products
opsonized cells are usually eliminated in the spleen
opsonization and phagocytosis
antibodies bound to cellular or tissue antigens activate classical pathway
inflammation
in some cases, antibodies are directed against cell surface receptors impair or dysregulate cell function, but do NOT cause cellular injury or inflammation
antibody mediated cellular dysfunction
name this disease, a type II antibody mediated response?
TSH receptor
antibody mediated stimulation of TSH receptors
hyperthyroidism
graves disease
name this disease, a type II antibody mediated response?
acetylcholine receptor
antibody inhibits acetylcholine binding, down modulates receptors
muscle weakness, paralysis
myasthenia gravis
what is this type of hypersensitivity reaction?
occurs when antigen-antibody complexes induce inflammatory response which may cause tissue damage
antigens can be endogenous or exogenous
type III immune complex
name this type of type III immune complex:
formation of antigen antibody complexes in circulation
deposition of immune complexes in various tissues
immune complex mediated inflammation and tissue injury
*this is a prototype of systemic immune complex disease where the antibodies react with antigen in circulation forming antigen antibody complexes
systemic
*acute serum sickness
name this type of type III immune complex:
localized area of tissue necrosis resulting from acute immune complex vasculitis after antigen is injected into skin
localized
what is this type of type IV hypersensitivity reaction?
- 12-48 hours
- mediated by CD4+ cells
- TB, fungi, protozoa, contact skin
- graft rejection
- edema
- -tuberculin skin test
delayed-type hypersensitivity
what is this type of type IV hypersensitivity reaction?
- CD8+ cytotoxic T-cells
- graft rejection
- respond to viral infection and tumor cells
- perforin-granzyme system
t-cell mediated cytotoxicity
most significant blood group antigen system for transfusion
antigens A,B,H
the ABO system
the major antigen, controlled by a single gene locus
autosomal dominant, locus D
D positivity confers Rh positivity
the D antigen
last double check to prevent transfusion of incompatible RBCs
cross matching
combs test that detects presence of immunoglobulin, complement or both coating the surface of RBCs
direct antiglobin test (Combs test)
like type and screen except crossmatch is performed
type and cross
