Inflammation 2.3: 1a Immunodeficiency

Question 1

Ca++ status in DiGeorge? Why?

Answer 1

hypocalcemia bc of lack of parathyroid glands

Question 2

T-cell status in DiGeorge? Why?

Answer 2

deficient; lack of thymus

Question 3

Heart findings in DiGeorge?

Answer 3

Tetralogy of Fallot, VSD, great vessel abnormalities

Question 4

T-cell deficiency –> problems fighting ____ and ____.

Answer 4

viruses; fungi

Question 5

4 parts to Tetralogy of Fallot?

Answer 5

• pulmonic stenosis
• increased thickening of the right ventricle
• VSD
• overriding aorta

Question 6

Tetralogy of Fallot heart sounds?

Answer 6

normal S1 and S2 with a blowing systolic murmur

Question 7

What is defective in SCID?

Answer 7

cell mediated and humoral immunity (both B cells and T cells)

Question 8

Name 3 etiologies causing SCID.

Answer 8

1. cytokine receptor defects
2. adenosine deaminase deficiency (auto recessive)
3. MHC Class II deficiency

Question 9

What is the inheritance of SCID?

Answer 9

either X-liked or auto recessive

Question 10

Why is adenosine deaminase deficiency bad?

Answer 10

build-up of adenosine and deoxyadenosine within lymphocytes –> lymphocyte toxicity

Question 11

What is the job of the CD4+ T-cell?

Answer 11

to help CD8+ T-cells and B cells become activated

Question 12

SCID pts are susceptible to _____.

Answer 12

fungal, viral, bacterial, and protozoal infections

Question 13

What is the tx for SCID?

Answer 13

sterile isolation and stem cell transplants

Question 14

How does SCID present in an infant?

Answer 14

failure to thrive, chronic diarrhea, thrush

Question 15

What causes X-linked agammaglobulinemia?

Answer 15

disordered B cell maturation (naïve B cells can’t mature into plasma cells) due to a tyrosine kinase mutation

Question 16

How does X-linked agammaglobulinemia present?

Answer 16

enterovirus, bacteria, and Giardia infections AFTER age 6 mos

Question 17

What is deficient in CVID ?

Answer 17

low Igs bc B-cells and Th cells are defective

Question 18

Helper T cells produce ____ and ____ to help B cell growth, maturation, and class switching.

Answer 18

IL-4 and IL-5

Question 19

How does CVID present?

Answer 19

usu. asymptomatic, but susceptible to enterovirus, bacteria, and Giardia infections IN LATE CHILDHOOD

Question 20

CVID pts are at increased risk for _____.

Answer 20

autoimmune diseases and lymphoma

Question 21

What is the most common Ig deficiency?

Answer 21

IgA

Question 22

What is mutated in Hyper IgM syndrome?

Answer 22

CD40L or CD40 receptor

Question 23

Name 2 ways B cells can be activated.

Answer 23

1. naïve B cell binds an antigen to the IgM receptor
2. B cell internalizes and presents antigen on MHC2 to a CD4+ T-cell, PLUS CD40 binds to the T-cell to activate it and produce IL-4 and IL-5, which mature and cause class-switching of the B cell

Question 24

What do low Igs in Hyper IgM Syndrome cause?

Answer 24

recurrent pyogenic infections, esp at mucosal sites

Question 25

What are the symptoms of Wiskott-Aldrich Syndrome?

Answer 25

1. thrombocytopenia (increased risk of bleeding)
2. eczema
3. recurrent infections (both humoral and cell mediate immunity deficient)

Question 26

What causes Wiskott-Aldrich Syndrome? What is its inheritance?

Answer 26

mutation in WASP gene; X-linked

Question 27

C5-C9 deficiency causes increased risk of ____.

Answer 27

Neisseria infections

Question 28

C1 inhibitor deficiency causes increased risk of ____.

Answer 28

edema of skin (periorbital) and mucosal surfaces (Hereditary Angioedema)