Hypersensitivity & Vaccines Flashcards
Do all hypersensitivity (allergic) reactions require previous exposure to the antigen (allergen)?
Yes
What are the 4 types of hypersensitivity reactions?
Type 1 (allergy) Type 2 (cytotoxic) Type 3 (immune complex-mediated) Type 4 (delay cell-mediated)
Which antibody is associated with Type 1?
IgE
Which antibodies are associated with Type 2?
IgG, IgM
Which antibodies are associated with Type 3?
IgG, IgM
Which antibodies are associated with Type 4?
None
What type of antigen is associated with Type 1?
Exogenous
What type of antigen is associated with Type 2?
Cell bound
What type of antigen is associated with Type 3?
Soluble
What type of antigen is associated with Type 4?
Tissues and organs
Rank the types of hypersensitivity reactions from fastest to slowest response time
Type 1
Type 2
Type 3
Type 4
What are examples of Type 1?
Allergic athsma, hay fever
What are examples of Type 2?
Erythroblastosis foetalis (HDN)
What are examples of Type 3?
SLE, Farmer’s lung
What are examples of Type 4?
Tuberculin test, poison ivy, granuloma
Where does immune complex deposition typically occur for type 3?
Skin, joints & kidney
What are the two types of anaphylaxis and what is the difference between the two?
Systemic anaphylaxis (immediate + life threatening) Localized anaphylaxis (not serious, only discomfort)
What are the 3 steps of developing a hypersensitivity reaction?
- Sensitization
- Activation
- Effector
Sensitization is the ____ exposure to the antigen
first
Activation is the ____ exposure to the antigen
second
What are 4 symptoms of systemic anaphylaxis?
- Impaired breathing due to swelling of airways
- Smooth muscle contraction
- Edema fluid leaks into tissue space
- Blood vessels dialate, BP drops (leads to shock)
What are 2 ways to treat hypersensitivity?
Antihistamines and epi-pen
What do antihistamines do?
Block action of histamine
What does an epi-pen do?
- Constricts blood vessels, lower BP
- Dilates airways in lungs
- Effects smooth muscle
What is a preventitive measure for Rh sensitization in pregnant women?
Rhogam is given before + after deliver to mother
What are 5 types of vaccines?
- Attenuated whole-agent
- Inactivated whole-agent + subunit
- Toxoids
- Conjugated
- Nucleic acid
For attenuated whole-agent vaccines, the microbe is ____
attenuated
Attenuated whole-agent vaccines can’t be used on:
Immunocompromised & pregnant women
Which type of vaccine mimics a real infection?
Attenuated whole-agent
How effective are attenuated whole-agent vaccines and how long does the immunity last?
Highly effective, often life-long immunity
For inactivated whole-agent + subunit vaccines, the microbes ____ or ____ of the organism are used
killed, parts
What 2 types of immunity are stimulated by attenuated whole-agent vaccines?
Humoral & cell-mediated immunity
For inactivated whole-agent + subunit vaccines, how long does the immunity last?
Immunity doesn’t last as long + requires boosters
Are inactivated whole-agent + subunit vaccines safe for immunocompromised people?
Yes
Inactivated whole-agent + subunit vaccines result in what type of memory?
B cell
How do you create toxoid vaccines?
Toxin is isolated & chemically treated to be non-functional
For toxoid vaccines, the body produces antibodies to the ____ not the microbe
toxin
For toxoid vaccines, how long does the immunity last?
Immunity doesn’t last as long + requires boosters
Polysaccharides are ___ antigens whereas proteins are ___ antigens
poor, good
An example of an attenuated whole-agent vaccine is:
Polio (Sabin), MMRV (mumps, measels, rubella, varicella)
An example of an inactivated whole-agent + subunit vaccine is:
Polio (Salk), rabies, influenza, Hep B
An example of a toxoid vaccine is:
Diptheria, tetanus
What is a conjugated vaccine?
Polysaccharides combined with a protein that is highly immunogenic
Why are conjugated vaccines used?
Children can’t respond to microbes with polysaccharide capsules (poor antigen)
An example of a conjugated vaccine is:
Neisseria meningitidis, streptococcus pneumoniae, haemophilus influenzae type b
What are nucleic acid vaccines?
DNA vaccines
How do nucleic acid vaccines work?
Introduce a gene of an organism into human host cells for it to persist + transcribe proteins
What does the tuberculin skin test determine?
Previous exposure to tuberculosis antigens
What cells does the tuberculin skin test detect?
Memory cells
Can the tuberculin skin test be used on immunocompromised + anergic people?
No
What are the steps of the tuberculin test?
- Inject PPD (purified protein derivative) into the skin of the forearm
- Check the area 48-72 hours later
What are the signs of a positive result of the tuberculin test and what does this indicate?
Reddening & thickening, indicates previous exposure to TB
What is the newer blood test for TB called?
QuantiFERON-TB Gold Test
What does the QuantiFERON-TB Gold Test test for?
Memory cells & activated T lymphocytes by production of IFN
What are the 4 types of adaptive immunity?
- Narturally acquired active immunity
- Narturally acquired passive immunity
- Artificially acquired active immunity
- Artificially acquired passive immunity
How do you get narturally acquired active immunity?
Exposed to the antigen in daily life and develop immunity after
How do you get narturally acquired passive immunity?
Natural transfer of antibodies (ie. mom to baby)
How do you get artificially acquired active immunity?
Vaccinated with specially prepared antigens
How do you get artificially acquired passive immunity?
Transfer of antibodies from an immunized individual to a non-immunized individual
Explain the process of acute systemic anaphylaxis happened in the body.
Mast cells start to pump out histamine and leukotrienes. Histamine increases the permeability of the blood vessels (so they leak and the blood pressure drops) and leukotrienes affect smooth muscle, causing bronchospasm and swelling of the throat.
