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Eosinophils/IgE - Type 2 vs Type 1 HS ?

Discussion in 'Step I' started by winsicle, Mar 29, 2007.

  1. winsicle

    winsicle Member
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    I had a ? on Qbank about what type of HS reaction in Ascaris infection. The answer was Type 1.

    I thought that invasive worms induce a Type 2 HS (cytotoxic reaction) wherein the eosinophil's IgE receptors bind to the organisms "IgE-like" surface ligands --> releasing MBP, etc. killing the organism.

    What am I missing here?
     
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  3. Pinkertinkle

    Pinkertinkle 2003 Member
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    Isn't type II IgG mediated?
    When I hear IgE I pick type I HS.
     
  4. leverp2000

    leverp2000 Senior Member
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    So the key is that Type II = antibody stimulating complement (IgG and IgM are the ones that do this). The reaction you described with IgE is not complement mediated. You should get the mast cell degranulation and release of histamine with a hellminth infection (immediate hypersensitivity), but the infection is frequently asymptomatic becasue the hellminth doesn't invade tissue all that often (it just crawls around and sometimes plugs up your bile duct).
     
  5. winsicle

    winsicle Member
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    Hmm, looking at Goljan's RR (pg. 40/44-45) he describes IgE mediated type I AND II HS, so what's the deal here - is HE wrong or is QBank wrong?

    and BTW he states the IgE-mediated type 2 reaction as Complement-independent
     
  6. Taus

    Taus .
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    you can have a type 2 using IgE-eosinophil killing (it doesn't need complement to make it a type 2...just an antibody to a cell).....but if the worm isn't "invasive" you won't get that mechanism and type 1 will predominate
     
  7. GOGETA

    GOGETA SuperSaiyan
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    Elevated Eosinophils= cancer, asthma,parasites,allergies.ect.

    Also remember that

    Type 1 the mast cells well degranulate, and you will have high IgE

    Type 2 The cell will say Hey dude inside of me there is a :thumbdown:, so kill me before its spreads.

    I hope this helps
     
  8. buddindoc

    buddindoc Senior Member
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    Type 1 hsn rxn
    NAACP---true
    but...
    Also remember that ONLY
    INVASIVE HELMINTHS CAUSE INC IN EOSINOPHILS
    eg:strongy and hookworm
    NON INVASIVE...DONT INC EOSINOPHILS.
    eg: pinworm and adult ascaris

    ***larvae of ascaris invade and cause an increase of eos but the adult forms dont incvade.*****

     

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