Hypersesnitivity Flashcards
Hypersensitivity reactions are caused by the immune system and can lead to ___ for the host.
Damage
_____ : prior exposure to an antigen that resulted in production of antibodies and/or immune cells creative to that antigen. It is required for a hypersensitivity reaction .
Pre-sensitization
There are four types of hypersensitivity. 1 through 3 are ____ and 4 is ___.
Humoral
Cellular
Type I hypersensitivity reactions involves antibody ____. The antigen must be ____. ___ cell activation is the main effector mechanism.
Type of reactions:
IgE
Soluble
Mast
Allergic rhinitis, allergic asthma, atopic eczema, systemic anaphylaxis, some drug allergies
Type II hypersensitivity reactions involves antibody ___. Two pathways:
1. Cell or matrix associated antigen activating ___, ___, and ___ cells.
2. Cell surface receptor (antigen), ____ alters the singling.
IgG
Complement
Phagocytes
NK
Antibody
Type III hypersensitivity reaction involves antibody ____. Antigen is ___. The effector mechanism is activating ___ and ____.
Examples of reactions:
IgG
Soluble
Complement
Phagocytes
Serum sickness, Arthus reaction
Type IV hyper sensitivity is ___ ___ hypersensitivity (DTH) and involves ___ cells.
Delayed type
T cells
Table of the four types of hypersensitivity:
Type I: allergic response:
___ antibodies produced in response to initial exposure bind to receptors on ___ cells. On second exposure, ___ attached to the mast cells recognized the ___ and binds. ____ of the cell is triggered by release of histamine, leading to allergy symptoms.
IgE
Mast
IgE
Allergen
Degranulation
Type I hypersensitivity:
Antigen presenting cell activates ___ cells which produce IL-4. This activates __ cells and they become a plasma cell that produces ____ antibody. This antibody binds to ___ cells.
TH2
B
IgE
Mast
Type I hypersensitivity reactions are traditional ____, such as:
Allergies
Urticaria (hives), hay fever, eczema, food allergies, allergic asthma, anaphylaxis
Type I hypersensitivity:
Immediate response within minutes caused by antigen _____ IgE on a presensitized mast cell, ____ and release of histamine leading to _____.
Delayed response takes hours when mast cells produce ____ that attract eosinophils and other cytokines leading to ____ and tissue damage
Cross-links
Degranulation
Vasodilation
Chemokines
Inflammation
What factors impact development of type I hypersensitivity reactions?
Genetics, environment-hygiene hypothesis, microbial and other environmental exposure
If you’re exposed to something your body either develops a ___ response or an ____ response
Tolerant
Inflammatory
Treatments of type I hypersensitivity are typically ____, not curative and include:
Palliative
Antihistamines, bronchodilators, epinephrine, desensitization therapy
We utilize ___ __ hypersensitivity reactions to perform allergy testing
Type I
Type II hypersensitivity is ____ mediated. IgG and IgM bind to ___ ___ antigens resulting in cell death of the antibody coated cell via ____, ____ activation, ____ ___ mediated Inflammation, or by antibody binding blocking ___.
Antibody
Cell surface
Phagocytosis, complement, Fc receptor, function
Type II hypersensitivity cell destruction examples:
1. ___ ___ ___: incompatible blood transfusions, need to test Rh compatibility and blood type
2. ___ ___ ___: antibodies against RBC membrane antigens
3. ___ ____: anti-platelet antibodies destroy platelets
4. ___ ___ of the newborn: due to blood type incompatibility of mom and baby
Blood transfusion reactions
Autoimmune hemolytic anemia
Immune thrombocytopenia
Hemolytic disease
Type II hypersensitivity inflammation examples:
1. ___ ___: autoimmune disease mediated by anti-glomerular basement membrane antibodies that target alpha-3 chain of type IV collagen
2. ___ ___ ___: following streptococcus pyogenes infection. Activation of lectin complement pathway
Goodpasture syndrome
Acute rheumatic fever
Type II hypersensitivity cellular dysfunction examples:
Type III hypersensitivity is mediated by ___ ___ of IgG antibody. They become deposited in various tissue. The site depends entirely on ____ the complex deposits, not antigen specific
Immune complexes
Where
___ ___ is the classic example of type III hypersensitivity. Antibodies to foreign antigens travel around the body and ___ in tissue. This activates ____ leading to ____ and tissue damage.
Serum sickness
Deposit
Complement
Inflammation
In serum sickness, the immune complexes form by ____ protein and ___ protein resulting in fever, rash, and poly arthritis. Most common these day with ___ vaccination, _____, and immune modulated agents (_____).
Human
Non-human
Rabies
Anti-venom
rituximab
Type III hypersensitivity also occurs in autoimmune disease (additional T cell involvement):
1. ___ ___ ___: autoantibodies to nucleoproteins, cytoplasmic antigens, leukocyte antigens, clotting factors, etc.
2. ___ ___: IgM form abnormal complexes with IgG
Systemic Lupus erythematosus
Rheumatoid arthritis
