Immunodeficiency

Question 1

Chediak Higashi syndrome

Answer 1

abnormally large lysosomes in granulocytes due to a mutation in lyst gene. Granules can cause tissue damage, leukocytes have reduced chemotaxis and killing abilities
Clinical presentation: loss of skin pigment, eye abnormalities, increased susceptibility to infections and tumours

Question 2

Leukocyte adhesion deficiency

Answer 2

LAD1 - Defect on CD18
LAD2 - defect on sialyl lewis X
LAD3 - defective chemokine signalling
usually means death early in life, usually have neutrophilia, eosinophilia

Question 3

Canine Cyclical Neutropenia

Answer 3

in border collies! loss of neutrophils ever 11-12 days for about 3 days. enteric disease, mouth infections, bone disease. die young

Question 4

Complement deficiencies

Answer 4

C3 in canines - susceptible to infections

Porcine Factor H - overactive complement, die of renal failure

Question 5

SCID

Answer 5

*arabian foals!
death at 4-6 months, no functional lymphocytes. Mutation in DNA-PK, no VDJ recombination, lymphocytes do not recognize antigen (do not pass positive selection)

Question 6

Diagnosing SCID

Answer 6

1. low circulating lymphocytes
2. lack of IgM in serum before suckling
3. hypoplasia of lymphatic organs

Question 7

X-linked SCID

Answer 7

mostly in males. frequent infections. decrease in T cell numbers, particularly CD8+. B cell numbers may be normal. Mutation in IL-2R (stops T cell proliferation)

Question 8

some causes of secondary immunodeficiencies

Answer 8

drugs, malnutrition, chronic disease, stress, high intensity exercise, age

Question 9

Cortisol and immune response

Answer 9

Increased cortisol can lead to a decreased immune response