Immunology 2 - Primary Immunodeficiency

Question 1

What factors make up specific immunity?

Answer 1

Antibodies

Cellular immunity

Question 2

What factors make up non-specific immunity?

Answer 2

Complement

Phagocytes

Question 3

What is the difference between primary and secondary immunodeficiency?

Answer 3

Primary - Congenital

Secondary - Acquired

Question 4

Immunodeficiencies increase the risk of what?

Answer 4

Infection
Cancer
Autoimmunity

Question 5

Primary immunodeficiencies are broadly caused by what?

Answer 5

Mostly mutations

Some by autoimmunity

Question 6

Primary immunodeficiencies predispose patients to what?

Answer 6

Infections and tumours

Question 7

Primary immunodeficiencies are caused by abnormalities in what?

Answer 7

Innate immune system
Stages of lymphocyte development
Responses of lymphocytes to antigen stimulation

Question 8

Agammaglobulinaemias are caused by what?

Answer 8

X linked mutation

Autosomal recessive mutation

Question 9

Agammaglobulinaemias cause what?

Answer 9

Decreased serum Ig

Decreased B-cell numbers

Question 10

Generally, B cell deficiencies present how?

Answer 10

Increased Pyogenic bacteria
Enteric bacteria 
Reduced serum IG
Normal DTH reactions
Absent follicles (germinal centres)

Question 11

Generally, T cell deficiencies present how?

Answer 11

Pneumocystis jiroveci
Viruses
Atypical fungi
Normal/reduced Ig
Reduced DTH reaction
Normal follicles

Question 12

Repeated infections with encapsulated bacteria is a sign of what?

Answer 12

Defective antibody production

Question 13

IgG and IgA deficiency presents how?

Answer 13

Pneumococcus

Haemophilius spp

Question 14

Infections with staph, gram -ve, fungi are associated with what?

Answer 14

Reduced number/function of phagocytes

Question 15

Complement defects predispose to what?

Answer 15

Neisseria meningitidis meningitis

Question 16

T-cell defects predispose to what?

Answer 16

Infection with intracellular organisms (protozoa, viruses, intracellular bacteria), mycobacterium
Reactivated latent Herpes (Cold sores, shingles)
Recurrent Candida

Question 17

How does the severity T-cell immunodeficiency lead to a variation in Mycobacterium Tuberculosis presentation?

Answer 17

Mild - invasion outside lungs

Severe - widespread, low virulence mycobacteria

Question 18

What tumours are associated with low T-cell numbers?

Answer 18

(Herpesvirus-induced tumours)
Kaposi sarcoma
non-Hodgkin lymphoma

Question 19

What are the causes of primary immunodeficiencies?

Answer 19

Mutations
Polymorphisms
Polygenic disorders

Question 20

What are polygenic disorders?

Answer 20

Combined action of >1 gene

(can be) Caused by autoimmunity

Question 21

Polygenic disorders of the immune system typically affect what?

Answer 21

Antibodies

Question 22

How is Severe Combined Immunodeficiency treated?

Answer 22

Bone marrow transplant

Screening in newborns

Question 23

What mutations are associated with SCID?

Answer 23

Some autosomal

Some X-linked

Question 24

What is the function of Mannan-binding lectin?

Answer 24

Binds sugars in bacterial cell walls to activate complement

Polymorphismsin MBL increase risk of infections

Question 25

What are the common Polygenic Immunodeficiencies?

Answer 25

Common variable immunodeficiency IgA deficiency Specific antibody deficiencies

Question 26

How does Common variable immunodeficiency present?

Answer 26

``` 1 in 20,000 young people Low total IgG (others variable) Recurrent resp infections GI, skin, neuro infections Autoimmunity Family history ```

Question 27

How does Specific antibody deficiency present?

Answer 27

Recurrent pneumococcus or haemophilius infections IN SPITE of normal IgG Don't respond to polysaccharide antigens

Question 28

Autoimmune poly­endocrinopathy candidiasis ectodermal dysplasia causes what?

Answer 28

Frequent severe Candia infections Other autoimmunity Antibodies against IL-17

Question 29

Autoantibodies against interferon y causes what?

Answer 29

Recurrent mycobacterial infections

Question 30

How does Severe combined immunodeficiency present?

Answer 30

``` Defective T and B cells Recurrent Infection in first few weeks Diarrhoea FH neonatal death Very low lymphocytes ```

Question 31

How does Antibody Deficiency present?

Answer 31

Chronic/recurrent bacterial respiratory infections later in life

Question 32

How is Antibody Deficiency investigated?

Answer 32

IgG, A, M Exclude secondary immunodeficiency Specific Haemophilius/pneumococcus antibodies Complement/neutrophil function

Question 33

How are Primary immunodeficiencies treated?

Answer 33

Prophylactic antibiotics Immunoglobulin replacement therapy Stem cell transplantation Gene therapy

Question 34

How is SCID treated?

Answer 34

Avoid live vaccines Prophylaxis against Pneumocystis jiroveci Stem cell transplant

Question 35

What are the requirements for gene therapy?

Answer 35

Mutation identified Correcting mutation must improve condition/survival Must not cause malignancy

Question 36

Defective HLA genes lead to what?

Answer 36

MHC faults (leading to faulty antigen presentation)

Question 37

What conditions are associated with loss of antibodies from the body?

Answer 37

Kidney, Liver and Gut disease