Hypersensitivity & Autoimmunity

Question 1

How is diversity of the antibody repertoire generated?

Answer 1

Heavy and light chain pairing via RAG recombinases

Addition of random nucleotides by TdT

Question 2

Hypersensitivity Type 1 reactions are mediated by..?

Answer 2

IgE

Question 3

Describe what happens in a Hypersensitivity Type 1 reaction

Answer 3

IgE binds to Fc Epsilon receptor on the mast / basophil cells. Crosslinking causes degranulation and release of Histamine, Prostaglandin, Leukotrienes

Question 4

Give 4 examples of Hypersensitivity Type 1 reactions

Answer 4

Anaphylaxis
Eczema
Hives
Asthma

Question 5

Hypersensitivity Type 2 reactions are mediated by…? What does it lead to induction of?

Answer 5

IgG and IgM, and activation of complement cascade

Question 6

Give 3 examples of Hypersensitivity Type 2 reactions

Answer 6

1. Transfusion reaction
2. Haemolytic disease of Newborn (HDN)
3. Drug-Induced Haemolytic Anaemia

Question 7

Hypersensitivity Type 3 reactions are mediated by?

Answer 7

IgG and IgM

Question 8

Give examples of Hypersensitivity Type 3 reactions

Answer 8

1. Glomerulonephritis
2. Systemic Lupus 3. Erythmatous
   Rheumatoid Arthritis

Question 9

Hypersensitivity Type 4 is mediated by?

Answer 9

Mediated by cellular pathology, not antibodies

Question 10

Give 3 examples of Hypersensitivity Type 4 reactions

Answer 10

1. Celiac disease
2. Contact hypersensitivity
3. Delayed type hypersensitivity

Question 11

T cells develop in the thymus, but education of T cells is performed by…?

Answer 11

Thymic epithelial cells