Hypersensitivity

Question 1

What characterizes Type I HSR?

Answer 1

IgE cross linking
degranulation

Question 2

What characterizes type II HSR

Answer 2

IgG
complement/T cell activation

Question 3

What characterizes type III HSR?

Answer 3

Immune complexes

Question 4

What characterizes type IV HSR?

Answer 4

delayed
sensitized T cells
cytokines
macrophages

Question 5

What are the relevant IL’s in type I HSR?

Answer 5

IL-4
IL-13
IL-5

Question 6

What cells secrete IL-4?

Answer 6

NK1.1 T cells

Question 7

What cells secrete IL-13?

Answer 7

Th2 cells
Mast cells

Question 8

What is the role of IL-4 and IL-13?

Answer 8

activate B cells to initiate class switching (IgG to IgE)

Question 9

What secretes IL-5?

Answer 9

Mast cells

Question 10

What is the role of IL-5?

Answer 10

activation and production of eosinophils

Question 11

What type of allergy do high IL-5’s indicate?

Answer 11

inhalation allergy

Question 12

What defines an atopic individual?

Answer 12

higher than normal IgE and eosinophil levels

Question 13

What is the microbiome’s role in hypersensitivity?

Answer 13

microbiome promotes Tregs to prevent hypersensitivity

Question 14

What is the role of Tregs?

Answer 14

to suppress CD4 and CD8

Question 15

Where do Tregs ariise from?

Answer 15

Thymus

Question 16

What is expressed on/in T regs?

Answer 16

CD4+
CD25+
FOXP3+

Question 17

What is the function of FOXP3+

Answer 17

• maintains Tregs
• inhibits Th2 cells

Question 18

What causes IPEX syndrome

Answer 18

genetic deficiency in FOXP3+

Question 19

What does IPEX syndrome cause?

Answer 19

wide range of autoimmune disorders

Question 20

What process is lost in someone with IPEX syndrome?

Answer 20

ability to inhibit Th2 cells

Question 21

What causes type II HSR?

Answer 21

IgG binding to cells –> T cell or compliment destroys the cells

Question 22

What are 2 examples of Type II HSR?

Answer 22

-hemolytic anemia (Rh)
-transfusion mismatch

Question 23

What is the immune complex composed of in a type III HSR?

Answer 23

antigen + antibody + complement

Question 24

Is the arthus reaction local or systemic?

Answer 24

local type III

Question 25

Is serum sickness local or systemic?

Answer 25

systemic type III

Question 26

What is an example of a result of serum sickness?

Answer 26

glomerulonephritis

Question 27

What is the first step of type IV HSR

Answer 27

T cells are sensitized during first exposure

Question 28

During the second part of type IV HSR, T cells release ____ and activate ____

Answer 28

Release cytokines and activate macrophages

Question 29

What are the 4 T's of the type IV HSR?

Answer 29

- T cells - Transplant rejections - TB skin test - Touching