Block E

Question 1

Define Immunodeficiency

Answer 1

When one or more components of the immune system are defective, resulting in an impaired or absent response to infection

(Usually detected in patients by recurrent infections with the same pathogen

Question 2

Define 1Y Immunodeficiency

Answer 2

Caused by inherited mutations in genes that are involved in, or control, immune responses
Rare

Question 3

Define 2Y Immunodeficiency

Answer 3

acquired as a consequence of other diseases or arises due to environmental factors such as starvation or as a side effect of medical intervention

Question 4

Who is more likely to be affected by immunodeficiencies and why

Answer 4

Men because most are recessive and caused by mutations in gene products on the X chromosome

Question 5

Name a benefit (scientifically) of immunodeficiencies)

Answer 5

Gives insight into normal function of pathways of defence against infection
e.g. deficiencies of Ab, of complement or phagocytic function each increase the risk of infection by certain types of bacteria due to host defence involving binding of antibody, fixing of complement and phagocytosis

Question 6

Define Bc deficiencies

Answer 6

associated with inability to clear extracellular bacteria (e.g., staphylococci; streptococci) and some viruses, whose elimination depends on neutralising antibodies (e.g., enteroviruses)