ch8: hypersensitivity and immunodeficiency Flashcards
hypersensitivity
hyperactive/overactive immune system
immunodeficiency
under-reactive immune system
primary immunodeficiency
congenital, born with defect
hypogammaglobulinemia
where is the defect
not making enough antibodies, defect in THYMUS –> ineffective maturation of T cells
severe combined immunodeficiencies (SCIDS)
ALL lymphocytes affected by a dysfunction
–> reticular dysgenesis: don’t make ANY type of WBCs
secondary (acquired) immunodeficiency
contracted AFTER birth
examples of secondary immunodeficiency?
- nutritional
- iatrogenic
- trauma induced
- stress induced
- result of infectious disease
nutritional immunodeficiency
ex. scurvy: vitamin c deficiency
iatrogenic immunodeficiency
treatment for one disease → leads to immunodeficiency (chemotherapy, antimitotic drugs)
trauma induced immunodeficiency
physical trauma is the cause of decreased immunity
ex. Getting severe burns = more susceptible to infection
stress induced immunodeficiency
physical stress to the body (emotional trauma/eating disorders) more susceptible to infection
result of infectious disease
ex: HIV (knocks out helper t cells, more prone to viral infections = since t cells work harder in viral infections) → AIDS
ex. epstein barr virus - infectious mononucleosis (goes for b cells → more prone to bacterial infection) → can lead to Strep
what are some treatments of immunodeficiency
- IVIg: artificially acquired passive immunity; get antibodies from lab; can be given prophylactically (monoclonal antibodies)
- Stem cell and/or bone marrow grafts
- gene therapy (CRISPR)
hypersensitivity
exaggerated response to injury (or to a foreign and/or bening substance)
anaphylaxis
body releases a severe amount of histamine that causes systemic effects, severe drop in BP
cutaneous anaphylaxis
rapid skin reaction/allergen, much less serious (hives, rash), can progress into systemic form…
systemic anaphylaxis
systemic reaction involving multiple organ systems
anaphylactic shock
over-vasodilation → decrease in blood pressure → severe drop in BP = SHOCK
histamine is a _______ while epinephrine is a ______
vasodilator, vasoconstrictor
allergy
something that isn’t harmful but for some reason the body interprets as a threat
neoantigens
ex.?
foreign substances/allergens can combine with tissues …
- poison ivy –> antibody antigen complex deposit into tissue
autoimmunity
own tissues are being attached by immune system
- clonal deletion didn’t happen properly
alloimmunity
response to grafted tissue
autograft
no alloimmune response; tissue grafted from one part of body to another party of your body
isograft
no alloimmune response; graft for identical twin (genetically and immunologically identical)
allograft
graft from another person of the same species
- possible secondary immunodeficiency
xenograft
graft from different species
what kind of tissue is easier for body to accept and why?
connective tissue – fewer cells = less likely to have alloimmune response
acute rejection
graft rejected quickly
chronic rejection
graft rejection after months, years
hyperacute rejection
what nickname?
“white graft”
- really quick rejection within hours, white graft because tissue will look like it was bleached
type i hypersensitivity
ex.?
IgE → mast cell degranulation → release of histamine
- urticaria
- desensitization
urticaria
(wheel and flare reaction): hives → red rings with bumps
atopic
genetic predisposition, genetically prone to have allergic reaction to something
how does desensitization work?
(by repeated exposure OR allergy shots)
Blocking antibodies: usually IgG class (stick to allergen before it has time to cross link IgE and cause degranulation)
type ii hypersensitivity
antibodies bind to tissue-specific antigens → trigger phagocytosis (macrophage go to eat)
ADCC (Antibody Dependent Cellular Cytotoxicity) = NK cells gives the touch of death
type iii hypersensitivity
Ab-Ag complexes deposit in certain tissues
“Serum sickness”: formation of large big complexes of Ab-Ag got stuck in certain tissues → body tries to go after it = damage to tissues
- neutrophils can’t break it down + lyse themselves
- arthus reaction, raynaud’s phenomenon
arthus reaction
constant exposure, low grade, to a particular antigen
raynaud’s phenomenon
what protein is associated with this
decreased blood flow to extremities due to a reaction → white fingertips
cryoglobulins: body in cold, lower temperatures → triggers cryoglobulins = these abnormal proteins may clump together at body temps below 98.6 F
type iv hypersensitivity
STRICTLY T CELL MEDIATED, NO B CELLS (no antibodies)
Graft/tumor rejection, contact dermatitis, poison ivy, jewelry (nickel) etc
“Delayed type” → won’t react right away
