Immunodeficiencies

Question 1

Chronic Granulomatous Disease etiology

Answer 1

2/3 of cases are X-linked recessive

1/3 of cases are autosomal recessive

Question 2

CGD deficiency

Answer 2

Cytochrome B deficiency –> no NADPH oxidase

no oxidative burst, cannot recycle NADP

Question 3

Inflammation of the nares
Large granuloma in the neck
Severe gingivitis
Esophageal stricture caused by a granuloma

Answer 3

CGD

Question 4

Colorless nitroblue tetrazolium test

Answer 4

CGD (lacks NADPH oxidase, so cannot reduce NADPH)

Question 5

CGD treatment

Answer 5

Antibiotics

IFN-gamma

Question 6

What is always a ddx along with CGD?

Answer 6

Myeloperoxidase deficiency

Question 7

What test differentiates between CGD and Myeloperoxidase deficiency?

Answer 7

NBT test

CGD: colorless
MD: dark

Question 8

Clinical presentation:
Partial albinism
Peripheral neuropathy
Thrombocytopenia
Nystagmus

Answer 8

Chediak-Higashi syndrome

Question 9

Chediak-Higashi etiology

Answer 9

Defect in polymerization of microtubules in neutrophils:

1. Defective neutrophil migration
2. Failure of phagocytosis
3. Failure of lysosomal function in neutrophils

Question 10

Chediak-Higashi defective gene

Answer 10

CHS1 on chromosome 1

Question 11

Deficiencies in C5-C9 are susceptible to what kind of infection?

Answer 11

Neisseria

Question 12

Clinical presentation:
Facial edema
Abdominal pain
Asphyxiation

Answer 12

Hereditary angioedema

Question 13

Hereditary angioedema deficiency

Answer 13

C1 inhibitor

Question 14

XLA etiology

Answer 14

Bruton’s tyrosine kinase gene defect (Btk)

Intereferes with VDJ rearrangement –> pre-B cells cannot differentiate to B-cells, cannot make immunoglobulins

Question 15

XLA age of onset

Answer 15

6 months, after maternal immunity has worn off

Question 16

Clinical presentation:
Recurrent otitis media, diarrhea, pneumonia
Chronic bacterial (esp. extracellular) infections
Very young (babies)

Answer 16

XLA

Question 17

XLA diagnosis

Answer 17

No IgM
No IgA
Marked increase in IgG
T-cells normal

Question 18

What should you not give XLA patients?

Answer 18

LIVE VACCINES

Question 19

XLA defective gene

Answer 19

Btk

Question 20

Clinical manifestations:
Recurrent bacterial infections
Sinopulmonary infections
Sclerosing cholangitis
Increased incidence of autoimmune disease

Answer 20

Hyper IgM syndrome

Question 21

Hyper IgM etiology

Answer 21

Defective expression of CD40L on T-cells

Question 22

CD40L is also known as _____

Answer 22

CD154

Question 23

DiGeorge etiology

Answer 23

80-90% of cases are associated with a gene deletion located at 22q11

III-IV pharyngeal arch hypoplasia

Do not make T-cells

Question 24

DiGeorge clinical manifestations

Answer 24

Cardiac defects
Abnormal faces
Thymic aplasia
Cleft palate
Hypocalcemia
22

Question 25

Decreases peripheral blood lymphocytes
CD3+ markedly decreased
Serum calcium markedly decreased
CXR: no thymic shadow

Diagnosis?

Answer 25

DiGeorge