Hypersensitivity

Question 1

A severe, immediate and system wide harmful immune response to a non-pathogenic antigen is called what?

Answer 1

Anaphylaxis

Question 2

An immediate or delayed immune response to innocuous antigen often resulting in healthy tissue damage is called what?

Answer 2

Hypersensitivity reaction

Question 3

What are the four types of hypersensitivity reactions?

Answer 3

1-Type I (Degranulation)
2-Type II (Complement ADCC)
3-Type III (Antibody complex deposition)
4-Type IV (T cell sensitization)

Question 4

Which three hypersensitivity reaction types are humorally mediated?

Answer 4

Type I, II, III

*Type IV is cell-mediated

Question 5

Non-pathogenic antigens that illicit a type I hypersensitivity reaction are called what?

Answer 5

Allergen

*proteins or glycoproteins that interact with PRRs with enzymatic activity.

Question 6

What are three Allergen-IgE activation granulocytes?

Answer 6

1-Mast cells
2-Basophils
3-Eosinophils

Question 7

What are 4 examples of localized allergen response (type I hypersensitivity)?

Answer 7

1-Allergic rhinitis (hay fever)
2-Allergic asthma
3-Eczema
4-Food allergies

Question 8

What cells typically respond to a helminth infection?

Answer 8

CD4 Th2 cells (sensitize eosinophils, basophils and mast cells)

Question 9

TNF-a, histamine, heparin, Tryptase, chymase, cathepsin T and carboxypeptidase are all released by what?

Answer 9

Mast Cells

Question 10

What three systems are affected by mast cell activation/degranulation?

Answer 10

1-Gastrointestinal tract (expulsion by diarrhea/vomiting)
2-Airways (expulsion via coughing, sneezing, phlegm)
3-Blood vessels (Edema and inflammation, increase flow of antigen to lymph nodes)

Question 11

What cells are activated by mast cells and Th2 cytokines, express FCe receptors once activated and have highly toxic granules that promote further inflammation?

Answer 11

Eosinophils

Question 12

What is the hygiene hypothesis?

Answer 12

Reduced early developmental immune pressure causes poor immune education and an inappropriate pathogen identification, leading to allergy and autoimmune disorders

Question 13

Common allergens are related to what antigens?

Answer 13

Helminth specie antigens

Question 14

What are the two phases of allergic reactions?

Answer 14

1-Acute phase (mast cells)

2-Late phase (Eosinophils, main destructive phase)

Question 15

IgE coated mast cells are activated by antigen in the bloodstream entering tissue causing what rapid, systemic and deadly allergic reaction?

Answer 15

Anaphylactic shock

*Epinephrine halts this

Question 16

Repeated exposure to escalating dosages of allergies to reduce type I responses is called what?

Answer 16

Hyposensitization

*most effective allergy treatment

Question 17

What are 4 type I treatments?

Answer 17

1-Antihistamines
2-Leukotriene antagonists
3-Corticosteroids
4-Immunotherapeutics

Question 18

Antibodies against self antigen or complement and antibody directed cellular cytotoxicity are typical of what type of hypersensitization?

Answer 18

Type II

*Drug allergies, graft rejection, autoimmunity

Question 19

What is an example of Type II hypersensitivity that effect newborns?

Answer 19

Rh factor (if mother is Rh-, has Rh+ baby, she builds immune response. If she has another Rh+ baby, her IgGs will attack fetal blood)

*Rhogam is the drug that prevents B-cell activation and memory cell formation

Question 20

Inefficient immune complex clearance such as antigen-antibody lattices, antigens with high affinity for tissue surfaces, highly charged antigens or compromised phagocytosis are what type of hypersensitivity?

Answer 20

Type III

*complexes deposited in blood vessels and tissues. Innate inflammatory response.

Question 21

CD4 T cells and macrophages play a major role in what two phase Hypersensitivity type?

Answer 21

Type IV (cell-mediated delayed type)

*cell mediated, not humoral. Contact material acts as adjuvant

Question 22

Obesity, tissue damage, heart disease, unresolved infection, periodontitis and intestinal microbes can all cause what?

Answer 22

Chronic systemic inflammation