Primary Immunodeficiency

Question 1

DiGeorge
etiology
defect

Answer 1

22q11 = 3rd and 4th pouch defects

absent thymus

Question 2

SCID

most important etiology

Answer 2

ADA (adenosine deaminase) deficiency

• breaks down adenosine and deoxyadenosine
• if absent, adenosine and deoxyadenosine are toxic to lymphocytes

Question 3

SCID 3 etiologies

Answer 3

ADA deficiency (adenosine tox to lymphocytes)
MHC-II deficiency
cytokine receptor defects
autosomal recessive

Question 4

ADA deficiency

Answer 4

adenosine deaminase deficiency
adenosine and deoxyadenosine toxic to lymphocytes
death of lymphocytes (B-cells and T-cells)
SCID

Question 5

MHC-II deficiency

Answer 5

SCID

humoral and T-cell loss

Question 6

Cytokine receptor defects

Answer 6

SCID

Question 7

SCID leads to loss of

Answer 7

cytotoxic and humoral immunity

Question 8

Tx of SCID

Answer 8

stem cell transplant

Question 9

X-linked agammaglobulinemia
defect
result

Answer 9

Burtons TK defect
defective B-cell maturation
no humoral immunity

Question 10

X-linked agammaglobulinemia

presentation

Answer 10

recurrent infections 6 mo after birth

when mom’s IgG is gone

Question 11

X-linked agammaglobulinemia
Common variable immunodeficiency
**recurrent infections of what

Answer 11

bacterial, enterovirus, and giardia

*giardia because IgA deficiency

Question 12

Danger in X-linked agammaglobulinemia

Answer 12

don’t give live vaccines

bacterial, enterovirus, giardia

Question 13

Common variable immunodeficiency

etiologies

Answer 13

low Ig due to B-cell or CD4 defects

Question 14

IgA deficiency

complications

Answer 14

recurrent mucosal/viral infections

Question 15

Hyper-IgM syndrome
defect
manifestations

Answer 15

CD40 or CD40L defect
T-cells cannot help B-cells class switch
recurrent pyogenic infections

Question 16

Which cytokines are important for B-cell class switching

Answer 16

IL-4 and IL-5 from Th2 CD4+ T-cells

Question 17

Wiskott-Aldrich syndrome
defect
manifestations

Answer 17

WASP TK defect (X-linked)
thrombocytopenia, eczema, recurrent infections
defect in humoral and cellular immunity

Question 18

Which 1˚ immunodeficiencies are X-linked

Answer 18

X-linked agammaglobulinemia (ADA defect)

Wiskott-Aldrich syndrome (WASP TK defect)

Question 19

C5-C9 deficiencies

complications

Answer 19

recurrent Neisseria infections

Question 20

Hereditary angioedema due to

Answer 20

C1 inhibitor deficiency

Question 21

C1 inhibitor deficiency

complications

Answer 21

cannot turn off complement
hereditary angioedema
esp periorbital edema