Lecture 31: Allergy and Hypersensitivity

Question 1

Recall the types of hypersensitivity.

Answer 1

Question 2

Describe Type I Hypersensitivity.

Answer 2

Question 3

Describe antigens/allergens.

Answer 3

Question 4

Recall the phases of Type I Hypersensitivity.

Answer 4

Question 5

Recall the Sensitization Phase of Type I Hypersensitivity.

Answer 5

Question 6

Recall the effects of mast cell activation.

Answer 6

Question 7

Recall the physiological effects of mast cell degranulation.

Answer 7

Question 8

Recall Type I Hypersensitivity Immediate and late phase response

Answer 8

Question 9

Describe the immediated phase of Type I Hypersensitivity.

Answer 9

Question 10

Describe the late phase of type I Hypersensitivity.

Answer 10

Question 11

Describe the two outcomes of type II Hypersensitivity.

Answer 11

Question 12

Describe the Haemolyticdisease of the newborn.

Answer 12

Question 13

Recall the treatment of Haemolyticdisease of the newborn

Answer 13

Question 14

Describe type III Hypersensitivity.

Answer 14

Question 15

Recall the removal of immune complexes.

Answer 15

Question 16

Recall the different phases of immune complex clearance.

Answer 16

Question 17

Recall the mechanism of type III Hypersensitivity.

Answer 17

Question 18

Recall immune-complex mediated damage.

Answer 18

• Immune complexes deposit on basement membranes and blood vessel walls
  
  • Narrow (turbulence interrupts fluid flow)
• Vasculitis – deposition in blood vessel walls
• Glomerulonephritis – deposition in kidney basement membranes
• Arthritis – deposition in joint synovium and vessels

Question 19

Describe Type IV Hypersensitivity.

Answer 19

Question 20

Recall Examples of antigens and pathogens that induce DTH.

Answer 20

Question 21

Recall the Sensitisation phase of DTH.

Answer 21

Question 22

Recall Mechanism of contact hypersensitivity

Answer 22

Question 23

Recall the Stages of DTH reaction

Answer 23

Question 24

Recall the Role of Th1 cytokines and chemokinesin DTH reaction

Answer 24

Question 25

Recall the process of Eliciting a DTH reaction in response to contact-sensitizing agent

Answer 25

Question 26

Describe the Mantoux Test.

Answer 26

Question 27

Recall the examples of T-cell mediated DTH.

Answer 27

Question 28

Describe Celiac Disease.

Answer 28

• Type IV hypersensitivity (DTH)
• Not a true autoimmune disease
• High incidence in Europe (1/300)
• >95%patients are DQ2 +ve (some DQ8)
• Gene dosage – homogenous for DQ2 higher incidence
• Hypersensitivity to wheat, barley and rye (gliadins, gliadin like molecules) triggers autoimmunity and pathology

Question 29

Recall the role of gluten in Coleiac Disease.

Answer 29

• Gluten is a complex mix of glutamine and prolinerich poly-peptides (prolinecontent provides stability in intestine)
• Tissue transglutaminase(tTg) converts glutamine into glutamic acid (negative charge)
• Modified gluten peptides (gliadins) can bind with high affinity to HLADQ2 and HLADQ8 (preference for -vecharge at anchor positions) resulting in T cell activation
• Innate system can be triggered through unknown mechanisms Production of IL15, activation of IELs

Question 30

Recall examples of DTH to foreign antigens.

Answer 30