PRAC: Immunodeficiencies

Question 1

How does Flow Cytometry work?

Answer 1

• Fluids cause a stream of single cells to run through a laser
• The laser causes a series of refractions and reflections
• Forward scatter detection shows the SIZE of the cell (lymphocytes are small compared to granulocytes)
• Side scatter shows HOW GRANULAR a cell is (more granules = more side scatter)
• Fluorescence is also used to show specific antibodies.
• Dot plots display the results

Question 2

What are Primary immunodeficiencies?

Answer 2

Inherited/Hereditary conditions

Question 3

What are Secondary Immunodeficiencies?

Answer 3

Acquired conditions (diabetes, HIV, Immunosuppression etc. )

Question 4

What are the three steps of phagocytosis?

Answer 4

1. Migration & recognition
2. Engulfment
3. Killing via respiratory burst

Chronic Granulomatous disease is a condition that impairs the ability of phagocytes to kill pathogens

Question 5

What is indicated by a purulent discharge (pus)?

Answer 5

Neutrophil migration and death has occured in response to the injury/infection

Question 6

Where is CD3 expressed?

Answer 6

CD3 is expressed on all T lymphocytes and stabilises the TCR

Question 7

Where is CD14 expressed?

Answer 7

Monocytes

Question 8

Explain CD18.

Answer 8

CD18 is heavily involved in adhesion and contains LFA-1, Mac-1, gp150,95

If CD18 is not expressed then Leukocyte Adhesion Deficiency occurs

Question 9

Macrophages have many functions:

Answer 9

• Healing processes
• phagocytosis
• APCs
• debris clearing
• signaling

Question 10

How can T cell/B cell function be assayed?

Answer 10

Look at Ig levels and the ratios of different isotypes for B cell function.
T cell function can be identified by looking at proliferation levels in the presence of infection as well as CD40L expression (which is only present on activated T cells and is used to activate B cells to begin isotype switching)

If CD40L expression is not present then Hyper IgM immunodeficiency can occur

Question 11

What does pancytopenic mean?

Answer 11

It is a decrease in the levels of all WBCs. It can happen due to ALL (Leukemia) conditions.

Question 12

How would you treat a child with secondary immunosuppression who has a viral infection?

Answer 12

Anti-viral therapies and isolation from others

Prevention could have been to vaccinate before immunosuppression.