CHAPTER 15

• How is hypersensitivity defined?


  Abnormal immune reactivity causing harm
• What happens when a patient is exposed to an innocuous antigen?

  Adverse reactions can occur, classified as immediate or delayed
• What are the general differences among the types of hypersensitivity?

  • Type 1: Allergic Hypersensitivity, immediate (hours)
  • Type 2: Cytotoxic Hypersensitivity, 5 to 8 hours
  • Type 3: Immune Complex Hypersensitivity, 2 to 8 hours
  • Type 4: Cell-Mediated Hypersensitivity, after 24 hours
• What is the immune reactant for Type 1 hypersensitivity?

  IgE
• What type of antigen is involved in Type 1 hypersensitivity?

  Soluble Antigen
• What is the effector mechanism for Type 1 hypersensitivity?

  Mast-Cell Activation
• What is an example of Type 1 hypersensitivity?

  Allergic Rhinitis
• What is the marker for helper T cells?

  CD4
• What cytokine activates B lymphocytes in Type 1 hypersensitivity?

  IL-4
• What do activated B lymphocytes release?

  Memory Cells and Plasma Cells
• What hormone is released during mast cell degranulation?

  Histamine
• What are the effects of mast cell activation in the gastrointestinal tract?

  • Increased fluid secretion
  • Increased peristalsis
  • Leads to vomiting or diarrhea
• What are the effects of mast cell activation in the airways?

  • Decreased diameter
  • Increased mucus secretion
  • Leads to wheezing, coughing, and nasal swelling
• What are common allergens for systemic anaphylaxis?

  Drugs, Serums, Venoms, Peanuts
• What is the route of entry for systemic anaphylaxis?

  Intravenous
• What are the responses associated with systemic anaphylaxis?

  Edema, Tracheal Occlusion, Circulatory collapse
• What are common allergens for acute urticaria?

  Animal hair, Insect bites
• What is the route of entry for acute urticaria?

  Through skin
• What is the response associated with acute urticaria?

  Local increase in blood flow
• What are common allergens for allergic rhinitis?

  Pollens, Dust-mite feces
• What is the route of entry for allergic rhinitis?

  Inhalation
• What is the response associated with allergic rhinitis?

  Edema of nasal mucosa
• What are common allergens for asthma?

  Danders, Pollens, Dust-mite feces
• What is the route of entry for asthma?

  Inhalation
• What is the response associated with asthma?

  Bronchial constriction and inflammation
• What are common allergens for food allergies?

  Tree nuts, Peanuts, Shellfish
• What is the route of entry for food allergies?

  Oral
• What is the response associated with food allergies?

  Vomiting, Diarrhea, Pruritus
• What occurs during anaphylaxis?

  Reaction becomes systemic and life-threatening
• What can cause a decrease in blood pressure during anaphylaxis?

  Fluid shift
• What are common signs of anaphylaxis?

  Urticaria, Angioedema, Dyspnea
• What antigens are associated with anaphylaxis?

  Proteins, Drugs, Foods, Insects
• What triggers allergic asthma?

  Allergen-induced activation of mast cells
• What is the role of bronchodilators in allergic asthma?

  They treat symptoms only
• What is the immune reactant for Type 2 hypersensitivity?

  IgG
• What type of antigen is involved in Mechanism 1 of Type 2 hypersensitivity?

  Cell or Matrix associated antigen
• What is the effector mechanism for Mechanism 1 of Type 2 hypersensitivity?

  Complement, FCR+ cells
• What is an example of Mechanism 1 in Type 2 hypersensitivity?

  Drug Allergies like penicillin
• What type of antigen is involved in Mechanism 2 of Type 2 hypersensitivity?

  Cell surface receptor
• What is the effector mechanism for Mechanism 2 of Type 2 hypersensitivity?

  Antibody alters signaling