Immunodeficiency

Question 1

When should an immune evaluation be performed?

Answer 1

When have two or more bacterial infections; unusual organisms are found; have a persistent infection

Question 2

What are some things other than immune deficiency that could cause persistent/unusual infections?

Answer 2

Burns (skin breakdown), ciliary immobility, CF

Question 3

What is the most common immunodeficiency? Is it always symptomatic?

Answer 3

Selective IgA deficiency- may be asymptomatic

Question 4

How is SCID inherited?

Answer 4

x-linked and autosomal recessive

Question 5

How is SCID treated? What happens if no treatment takes place?

Answer 5

BM transplant- no treatment then death

Question 6

What is the most common cause of SCID? Why is this so severe?

Answer 6

interleukin receptor gamma chain defect- effects the gamma chain in an array of cytokine receptors including IL-2R, IL-7R, IL-4R, IL-21R

Question 7

What is missing in SCID? Why are they missing?

Answer 7

T cells and B cells- missing because cytokine receptors have a defect so can’t get cytokine binding

Question 8

The misfunction of what cells can lead to immunodeficiency?

Answer 8

B cells (humoral), T cells (cell-mediated), phagocytes (cell-mediated), complement (cell-mediated)

Question 9

What type of immunodeficiency is x-linked agammaglobulinemia?

Answer 9

Humoral immunodeficiency

Question 10

What causes the lack of B cells seen in x-linked agammaglobulinemia?

Answer 10

Mutation in Bruton’s tyrosine kinase (BTK)- needed for B cell maturation

Question 11

What are some quantitative measures that would show you a patient has humoral immunodeficiency?

Answer 11

Higher quantity of IgM, inability to produce a high titer even after vaccination

Question 12

What would CD40L deficiency cause?

Answer 12

B cells can’t be activated; humoral immunodeficiency, hypogammaglobulinemia with a lot IgM because can’t class switch; inability to activate macrophages

Question 13

What would lymph nodes look like when there’s a CD40L deficiency?

Answer 13

No germinal centers; no B cell class switching of affinity maturation

Question 14

When a patient is complement deficient, what types of infections are they more susceptible to?

Answer 14

Neisseria

Question 15

A patient with SCID is given a Tetanus vaccine. What is the response?

Answer 15

Nothing happens- not harmful, but also not really beneficial

Question 16

What is a neutrophil defect known as?

Answer 16

Chronic granulomatous disease

Question 17

Why do granulomas form in chronic granulomatous disease?

Answer 17

Neutrophils are present but not functional; so they need extra help from activated macrophages

Question 18

A phagocyte deficiency makes the patient more susceptible to what kinds of infections?

Answer 18

Catalase positive bacteria (Staph)

Question 19

What are the abnormalities seen with DeGeorge syndrome?

Answer 19

Abnormal development of the 3rd and 4th pharyngeal pouches, resulting in thymic hypoplasia/aplasia and hypoparathyroidism which leads to heart disease

Question 20

Those with DeGeorge are more susceptible to what kinds of infections?

Answer 20

Viral and fungal disease

Question 21

How is DeGeorge treated? Is a BM transplant effective?

Answer 21

Thymic transplant- BM transplant isn’t effective because still doesn’t have a thymus that T cells can mature in