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Flashcards in Primary Immunodeficiencies Deck (33):
1

DiGeorge syndrome is due to what failure of development?

Failure of formation of the 3rd and 4th pharyngeal pouch

2

What is the gene mutation with DiGeorge syndrome?

22q11 microdeletion

3

What are the three classic findings of patients with DiGeorge syndrome?

Abnormalities of the face
Hypocalcemia
T-cell deficiency

4

What is the pathophysiology behind the T cell deficiency seen in DiGeorge syndrome?

Lack of a thymus

5

What is the pathophysiology behind the hypocalcemia seen in DiGeorge syndrome?

No parathyroids thus no PTH

6

What two types of pathogens are pts with DiGeorge syndrome susceptible to?

Viruses
Fungi
(these are T cell mediated defenses)

7

Which types of immunity are affected in SCID: humoral or cell mediated?

Both

8

What are the three major etiologies of SCID?

1. Cytokine receptor defects
2. Adenosine deaminase deficiency
3. MHC class II deficiency

9

Why does an adenosine deaminase deficiency result in SCID?

Inability to deaminate adenosine results in accumulation of toxic adenosine in lymphocytes

10

Why does MHC class II deficiency result in SCID?

No CD4+ Th cell activation, thus no helper cells (T-helper cells are the conductors of the immune system)

11

What is the treatment for SCID?

Stem cells transplant in bone marrow

12

What is the pathophysiology behind X-linked agammaglobinemia?

Disordered B cell maturation, leading to a complete lack of immunoglobin

13

What is the protein that is mutated in X-linked agammaglobinemia?

Bruton Tyrosine Kinase

14

What are the three infections that pts with X-linked agammaglobinemia are susceptible to?

Bacterial
Enterovirus
Giardia

15

What patients must avoid live vaccines? (2)

X-linked agammaglobinemia
SCID

16

Why is it that pts with X-linked agammaglobinemia do not present with symptoms before 6 months of age?

Still have maternal antibodies

17

What is the pathophysiology behind common variable deficiency?

Low immunoglobin d/t B cell or Th cell defects

18

What are the three infections that CVID pts are susceptible to?

1. Bacterial
2. Giardia
3. Enterovirus

19

What is the malignancy that CVID pts are susceptible to? Why?

B cell lymphoma d/t proliferation of B cells

20

What is the pathophysiology behind IgA deficiency?

Low serum IgA, leading to an increased risk for mucosal infections

21

What is the most common immunoglobin deficiency?

IgA deficiency

22

Which GI disease is associated with IgA deficiency?

Celiac disease

23

What type of infections are patients with IgA deficiencies susceptible to?

Mucosal infections, especially viral

24

What is the mutation involved in hyper IgM syndrome?

Second cell signals to B cells (CD40 ligand) do not function, thus no class switching from IgM

25

What are the two ways in which B cells are activated?

Antigen binds IgM on cell surface

B cell internalizes antigen, and presents to CD4+ Th cells

26

When CD4+ T cells are activated by B cells, what two cytokines do they produce to induce B cells to switch from IgM to other immunoglobin classes?

IL-4
IL-5

27

Why is there still adequate amounts of IgM in hyper IgM syndrome?

B cells can still be activated via IgM binding to antigens on cell surface receptor

28

What are the three symptoms of Wiskott-Aldrich syndrome?

1. Thrombocytopenia
2. Eczema
3. Recurrent infx

29

What is the mutation involved in Wiskott-Aldrich syndrome (what gene on what chromosome)?

Defect in the WASP gene on the X chromosome

30

Deficiency if C5-C9 pose an increased risk with what infection in particular?

Neisseria (gonorrhea, meningitis etc)

31

C1 inhibitor deficiency causes what physical symptoms?

Hereditary angioedema

32

What is the pathophysiology behind C1 inhibitor deficiency?

Not inhibiting C1 will lead to chronic edema and inflammation d/t no inactivation of complement

33

C1 inhibitor deficiency causes what physical symptoms?

Hereditary angioedema--periorbital edema especially