Lecture 13- Immune dysfunction part 2

Question 1

What are the ways to diagnose allergies?

Answer 1

1. Symptoms
2. Blood test
   
   1. Look at blood titers (IgE)
3. Skin test
   
   1. Skin is exposed to allergen, look for wheal and flare lesion

Question 2

What are the four ways to manage type 1 allergies?

Answer 2

1. Avoid antigen
2. Antihistamines (benadryl)
3. Steroid treatments
4. Antibody treatments (xolair)

Question 3

How do these treatments work:

• antihistamines
• Steroid treatments

Answer 3

• antihistamines= block histamines from binding to host receptor
• steroid treatments= decrease symptoms, but cause immunosuppresion

Question 4

How do antibody treatments work?

Answer 4

Bind host IgE so they cannot bind allergens

Question 5

What is type 2 hypersensitivity?

Answer 5

IgG or IgM (antibody) binds non-soluble antigen.

• can be cell surface or extracellular tissue

Question 6

How do type 2 hypersensitivity allergens cause damage?

Answer 6

1. Cytotoxic damage
   
   1. Complement dependent
   2. Complement independent
2. non-cytotoxic damage

Question 7

What does cytotoxic, type 2 hypersensitivity do?

What are some examples?

Answer 7

Cause lysis of cells.

• Blood transfusion reactions
• Hemolytic anemia

Question 8

How does complement dependent, cytotoxic sensitivity work?

• (what binds to what)

Answer 8

• Antigens bind to host cell
• Antibodies bind to antigen
• complement porteins bind antibody

Question 9

What causes host cells to lyse due to complement dependent hypersensitivities?

Answer 9

• Membrane attack complexes form in host cell

or

• Immune cell phagocytose host cell

Question 10

How does complement independent hypersensitivity work?

(What binds to what)

Answer 10

• Antigens bind to host cell
• Antibodies bind to antigen

Question 11

What causes the host cell to lyse due to complement independent hypersensitivity?

Answer 11

Natural killer cells destroy host cell

Question 12

What happens during non-cytotoxic damange by type 2 hypersensitivity?

Answer 12

Cell does not lyse.

antibodies bind to host cell receptor.

Question 13

What two things can occur due to non-cytotoxic, type 2 hypersensitivity?

Answer 13

1. Inactivates natural host receptor
2. Over-stimulate natural host receptor (overactive thyroid)

Question 14

What dictates the difference in blood types?

• A, B, and O
• Rh factor (positive or negative)

Answer 14

• A, B, and O are carbohydrate based
• Rh factor is protein based
  compatibility is based on surface antigens

Question 15

What is hemolytic transfusion reaction?

Answer 15

When blood transfusions are not a match and cause immune cells to lyse RBC.

Question 16

What is the universal acceptor blood type?

What is the universal donor blood type?

Answer 16

Universal acceptor= AB+

Universal donor= O-

Question 17

What happens if a baby’s Rh factor is different from a mother’s in a second pregnancy?

Answer 17

Mother’s antibodies cross placenta and target baby’s RBC

Question 18

What is type 3 hypersensitivity?

Answer 18

IgG or IgM antibodies bind soluble antigens and make antigen-antibody complexes

• complexes collect in tissue and cause massive inflammation

Question 19

What are the two types of type 3 hypersensitivities?

Answer 19

1. Autoimmune type (lupus)
2. Non-autoimmune type (venom)

Question 20

What are type 4 hypersensitivities?

• What is it also known as?

Answer 20

T-cell mediated (not antibody mediated)

• called delayed hypersensitivity as it can take up to 3 days for reaction

Question 21

What are the 2 types of Type 4 hypersensitivity?

Answer 21

1. Autoimmune type (multiple sclerosis)
2. Non-autoimmune type (TB skin test)

Question 22

• What occurs during an autoimmune type 4 hypersensitivity?
• Multiple sclerosis?

Answer 22

T-cell attacks localized (not systemic) specific tissue

• T-cell see normal self antigen on myelin sheath, attack and destroy cell

Question 23

What are non-autoimmune type 4 hypersensitivities caused by?

Answer 23

Caused by haptens

• molecules too small to cause reaction but bind host cell proteins to cause reaction

Question 24

What are type of hypersensitivity are transplant rejections?

Answer 24

Type 4, non-autoimmune

Question 25

Name these types of transplants:

• Between same species
• From identical twins

Answer 25

• Allograft
• Isograft (least chance of rejection)

Question 26

Name these types of transplants:

• From different species
• From same person

Answer 26

• Xenograft
• Autograft (least chance of rejection