Primary Immunodeficiency - Pathoma

Question 1

SCID

Answer 1

severe COMBINED immunodeficiency: defective cell-mediated and humoral immunity

Question 2

etiologies of SCID

Answer 2

• cytokine receptor defects (–> lack of cytokine signaling which is necessary for prolif and maturation of B and T cells)
• adenosine deaminase (ADA) deficiency –> buildup of adenosine and deoxyadenosine which are toxic to lymphocytes)
• MHC class II deficiency (needed for CD4+ helper T cell activation and cytokine production)

Question 3

SCID treatment

Answer 3

sterile isolation; stem cell tcp

Question 4

X-linked agammaglobulinemia
What is it?
Cause?

Answer 4

COMPLETE LACK of immunoglobulin (Ig) due to mutated Bruton tyrosine kinase –> disorder of B-cell maturation (naive B can’t mature to plasma cells so can’t get Ig in blood)

Question 5

X-linked agammaglobulinemia presentation

Answer 5

• 6mo after birth (b/c have mom antibodies for 6mo after birth)
• recurrent bacterial, enterovirus, and Giardia infections
• don’t give live vaccines (ex: polio) !!

Question 6

CVID

Answer 6

common variable immunodeficiency disease = LOW Ig due to B-cell OR helper T-cell defects

Question 7

CVID presentation

Answer 7

• usually late in childhood - increased risk bacterial, enterovirus, and Giardia infections
• incr risk for autoimmune disease and lymphoma

Question 8

IgA deficiency

Answer 8

• low serum and mucosal IgA
• most common Ig deficiency
• incr risk mucosal infections, especially viral

Question 9

What deficiency is assoc w/ celiac disease?

Answer 9

IgA deficiency

Question 10

Hyper IgM syndrome

Answer 10

elevated IgM

• due to mutated CD40L or CD40 receptor (2nd signal can’t be delivered to helper T cells during B-cell activation)
• cytokines needed for Ig class switching aren’t produced –> low IgA, IgG, and IgE –> recurrent pyogenic infections, esp at mucosal sites

Question 11

Wiskott-Aldrich Syndrome presentation

Answer 11

• thrombcytopenia
• eczema
• recurrent infections (variety of them) - defective humoral and cellular immunity

Question 12

Wiskott-Aldrich Syndrome genetics

Answer 12

WASP gene

- X-linked

Question 13

Complement deficiency - Anything from C5-C9 puts at increase risk for —-

Answer 13

Neisseria infection

Question 14

C1 inhibitor deficiency

Answer 14

hereditary angioedema characterized by edema of skin (esp periorbital) and mucosal surfaces

Question 15

SCID presentation

Answer 15

• susceptibility to fungal, viral, bacterial, and protozoal infections including opportunistic infections and live vaccines

Question 16

DiGeorge Syndrome

Answer 16

Developmental failure of 3rd and 4th pharyngeal pouches due to 22q11 microdeletion

Question 17

DiGeorge Syndrome presentation

Answer 17

• T-cell deficiency (lack of thymus)
• hypocalcemia (lack of parathyroids)
• abnormalities of heart, great vessels, and face