Primary immunodeficiency

Question 1

what is the major consequence of immunodeficiency?

Answer 1

increased susceptibility to infection and cancer

also increased incidence of autoimmunity

Question 2

in primary immunodeficiency, where might the abnormality be?

Answer 2

component of the innate immune system
stages of lymphocyte development
responses of mature lymphocytes to antigenic stimulation

Question 3

what immune cell is defective if there are reduced serum Ig levels?

Answer 3

B cell deficiency

Question 4

what immune cell is defective if a patient has reduced delayed hypersensitivity reactions to common antigens?

Answer 4

T cell deficiency

Question 5

a patient with deficiency in what immune cell will have increased susceptibility to atypical mycobacterium infection such as TB?

Answer 5

T cell deficiency

Question 6

a patient with deficiency in what immune cell will have increased susceptibility to pnuemocystitis jiroveci infection?

Answer 6

T cell deficiency

Question 7

a patient with defciency in what immune cell will have increased susceptibility to pyogenic bacteria such as otitis, pneumonia, meningitis, osteomyelitis?

Answer 7

B cell deficiency

Question 8

a patient with deficiency in what immune cell will have an increased susceptibility to parasitic infections?

Answer 8

B cell deficiency

Question 9

a patient with a defect in phagocytes will have an increased susceptibility to what type of pathogens?

Answer 9

bacteria 
- staph
- gram negative
fungi 
- aspergillus 
- candida

Question 10

a patient with a defect in the complement system will have an increased susceptibility to what type of pathogens?

Answer 10

pyogenic bacteria

neisseria

Question 11

a patient with a defect in the antibodies will have an increased susceptibility to what type of pathogens?

Answer 11

pyogenic bacteria

• staphylococci
• strep pneumoniae
• haemophillus influenzar

some viruses

Question 12

a patient with a defect in the cellular immunity will have an increased susceptibility to what type of pathogens?

Answer 12

viruses 
- CMV 
- HSV
fungi 
- candida
- aspiergillus
- pnuemocystitis 
bacteria
- mycobacteria 
protozoal
- cryptospirodum

Question 13

recurrent respiratory infections by pnuemoccous or haemophillus spp is due to what defect in the immune system?

Answer 13

antibody production

Question 14

recurrent candida infections is suggestive of defects in what T cell pathway?

Answer 14

Th17 pathway

Question 15

what part of the immune system does polygenic disorders affect?

Answer 15

Antibodies

Question 16

what are the 3 main causes of primary immunodeficiency and what severity of disease do they cause?

Answer 16

polymorphs - minor changes
polygenic disorders
mutations - severe disease

Question 17

what is SCID and what part of the immune system does it affect?

Answer 17

severe combined immunodeficiency (SCID)

gene mutation that affects both T and B cells

Question 18

what is the treatment for SCID?

Answer 18

stem cell transplant
very soon after birth
+/- gene therapy

Question 19

what are polymorphs and what effect do they have in the immune system?

Answer 19

polymorphs involves one of 2 or more variants of a particular DNA sequence
in the immune system they cause increased risk of infection

Question 20

what is CVID?

Answer 20

common variable immunodeficiency

polygenic disorder

Question 21

in CVID, what immunoglobulin is deficient?

Answer 21

IgG

Question 22

what is the inheritance of CVID?

Answer 22

autosomal recessive

Question 23

what are some primary immunodeficiencies caused by?

Answer 23

autoimmunity

Question 24

what is the clinical presentation of a child with severe combined immunodeficiency (SCID) ?

Answer 24

develop infection within the first few weeks of life
unusual or recurrent infections
diarrhoea
unusual rashes

Question 25

how is SCID diagnosed?

Answer 25

flow cytometry to measure lymphocyte count

Question 26

at what lymphocyte count is diagnostic of SCID?

Answer 26

< 1 x 10 (9)/L

Question 27

when does common viral immunodeficiency (CVID) present ?

Answer 27

present later on in life due to the presence of maternal antibodies

Question 28

how is CVID diagnoseD?

Answer 28

IgA, IgM and IgG levels measured

if low - you have to consider secondary immunodeficiency before CVID
if normal test specific antibodies against haemophillus and pneumococcus

if both tests are normal then check that the problems aren’t due to complement or neutrophil function