Immunology Small Group sessions

Question 1

Mast cells are agranular. True/ False?

Answer 1

False.

Mast cells have large granules in their cytoplasms

Question 2

What is tryptase and why can it be used as a diagnostic tool for allergic reaction?

Answer 2

It’s a secretory granule released by mast cells upon their degranulation. It is stable enough to be used as a diagnostic tool (histamine is not stable enough). Measuring IgE and specific IgE levels is also diagnostically useful.

Question 3

Haemolysis is typical of type _ hypersensitivity?

Answer 3

3 (complement-mediated reactions)

Question 4

Less antigen is needed to trigger an anaphylactic reaction than an immune complex reaction. True/ False?

Answer 4

True

Also, an excess of antigen in relation to Ig levels is required for immune complex formation

Question 5

Granulomas are classic of type _ reactions?

Answer 5

4

Question 6

Complement activation is a key part of all hypersensitivity reactions, EXCEPT type _?

Answer 6

1

Question 7

What is Goodpasture’s syndrome AKA antiglomerular basement antibody disease?

Answer 7

A rare autoimmune disease in which Ig attacks the basement membrane in lungs and kidneys - leading to bleeding from lungs and kidney failure

Question 8

Myasthenia gravis is an autoimmune disease due to Ig being directed against acetylcholine receptors. What type of hypersensitivity is this?

Answer 8

2

Question 9

Which type of hypersensitivity occurs in response to soluble antigens?

Answer 9

3

Question 10

If a patient with asthma gets no relief from anti-histamines, what mediator is most likely to be causing their symptoms?

Answer 10

Leukotrienes
These are (in addition to histamine) released from mast cells, and can mediate many of the pathological effects associated with asthma

Question 11

Vasculitis is a common feature of which type of hypersensitivity?

Answer 11

3 (this type involves IgG and complement)

Question 12

Neutrophils are associated with allergy. True/ False?

Answer 12

False

Question 13

What are the only 2 cells which bind IgE?

Answer 13

mast cells and eosinophils (they bind to the Fc region on Ig)

Question 14

Which mediators induce fever?

Answer 14

TNFa and other pro-inflammatory cytokines

NOT histamine

Question 15

Sodium cromoglycate can be used to treat type 1 hypersensitivity. How?

Answer 15

It is a mast cell stabiliser which prevents mast cell degranulation

Question 16

How do activated T helper cells stimulate B cells to proliferate and differentiate into plasma cells (which then produce IgE)?

Answer 16

T helper cells produce cytokines

Question 17

In type 1 hypersensitivity, what causes wheeze?

Answer 17

• bronchial constriction
• mast cell degranulation (causes the constriction)
• histamine released from degranulation

Question 18

CD45+ is a lineage marker for what type of cell?

Answer 18

All WBCs

Question 19

CD3- is a lineage marker for what type of cell?

Answer 19

non-T cells
CD3-CD9+ = B cells
CD3-CD16+CD56+ = NK cells

Question 20

CD3+ is a lineage marker for what type of cell?

Answer 20

T cells only