Immunodeficiency

Question 1

Give 2 examples of hypersensitivity

Answer 1

• autoimmunity
• allergies

Question 2

What are the two types of immunodeficiency? [2]

Answer 2

• primary
• secondary (acquired)

Question 3

Define the term immunodeficiency

Answer 3

• state in which the immune system’s ability to fight infectious diseased is compromised or completely absent

Question 4

What are the four characteristics of infections in immunodeficiency?

Answer 4

• severe
• persistent
• unusual
• recurrent

Question 5

What does excess pus suggest about an infection

Answer 5

• high neutrophil count
• extracellular bacteria
• issues with antibodies, complement system or phagocytosis

Question 6

What is the most common primary immunodeficiency

Answer 6

• antibody: IgG

Question 7

Describe SCID [5]

Answer 7

• early onset
• maternal antibodies should protect child from early age, if bot something wrong with immune system
• diarrhoea
• failure to thrive
• lymphopenia

Question 8

Explain the result of gamma-chain mutation on the immune function

Answer 8

• gamma chain normally activates CD4+ cells
• makes IL-2 cytokines (T cell proliferation)

Question 9

Explain how deficiency in AID causes immunodeficiency [4]

Answer 9

• genetic mutation causing lack of activation-induced cytidine deaminase
• impacts class switching
• less IgG and IgA made, IgM production maintained
• IgM has lower affinity that IgG therefore more bacterial infections

Question 10

How would you expect the antibody levels to differ in healthy individual compared to someone with AID deficiency

Answer 10

• higher IgM count than healthy individuals
• less of the other antibodies

Question 11

What is secondary immunodeficiency

Answer 11

• deficiency in the immune function as a result of other factors

Question 12

Identify some examples of things that may cause secondary immunodeficiency [4]

Answer 12

• infection (HIV)
• malnutrition
• immunotherapy
• leukaemia

Question 13

What is flow cytometry [2]

Answer 13

• a method to measure and analyse multiple characteristics of cells
• as the flow through fluid stream through beam of light

Question 14

Describe how light scatter informs of the characteristics of cells [3]

Answer 14

• light scatter occurs when particle deflects laser light
• forward scatter informs about cell size (surface area)
• side scatter: tells us of the granularity of a cell (internal complexity)

Question 15

How can fluorescence tagging helps us to identify cell types [4]

Answer 15

• antibodies added
• tag specific markers
• seen uniquely on certain cell type
• analyse to determine which cell it is

Question 16

How can fluorescence tagging and flow cytometry be used together [5]

Answer 16

• tagged cells pass through 1 by 1
• light waves emitted from laser
• signals converted by computer
• to identify cekk
• can used to sort individual cells

Question 17

Graph