Montleleone - Primary Immunodeficiency

Question 1

Where is each Ig most commonly found?

Answer 1

IgG - extra vascular spaces 
IgM - first Ig made by the fetus
IgA - major Ig in secretions
IgD - in serum, not much is known.
IgE - binds to mast cells and basophils

Question 2

What is the most common type of primary immunodeficiency

Answer 2

Antibody deficiency

Question 3

What microbes are common in T cell infections?

Answer 3

Pneumocystis
Cryptococcosis
Herpesvirus
- you’ll see respiratory infections, diarrhea, failure to thrive

Question 4

What microbes will you see in B cells immunodeficiency?

Answer 4

Haemophilus, streptococcus, campylobacter, parasitic infections such as Giardiasis, and enteroviruses
- going to affect the lungs and nose

Question 5

What type of bacteria will you see in phagocyte immunodeficiency?

Answer 5

Staphylococcus, burkholderiA, serratia, norcadia, fungal infections such as aspergillus.
- patient will have recurrent infections and abscesses

Question 6

Main bacteria for monocyte immunodeficiency?

Answer 6

Nontuburculosus mycobacteria (respiratory)
Salmonella (GI)

Question 7

What type of bug would you see in a complement immunodeficiency?

Answer 7

Neisseria

Question 8

What are the main T cell deficiency diseases?

Answer 8

SCID
DiGeorge
Ataxia-telamgectasia
Wiskott-Aldrich syndrome

Question 9

SCID

Answer 9

Diminished or absent T cells
May or may not have B cell and NK cell impact depending on the gene mutation.
May die in first year of life without treatment.

Question 10

DiGeorge syndrome

Answer 10

Impacts organs derived from the 3rd and 4th pharyngeal arches

• teterology of Fallot
• low set ears and cleft palate
• hypocalcemia
• thymus is affected which leads to absent/low T cells

Question 11

Ataxia telangiectasia

Answer 11

Gene mutation that causes a defect in CD4 T cells.

• causes A deficiency in IgA and IgE
• neurological and progressive motor loss
• telangiectasias - spider veins

Question 12

Wiskott-Aldrich syndrome

Answer 12

T cell immune deficiency that also affects B cells.

• small palates and thrombocytopenia with petechiae, bruising, bleeding
• eczema
• upper respiratory and opportunistic infections
• high rate of autoimmunity and lymphoid malignancy

Question 13

Diseases associated with B cell deficiency

Answer 13

Agammaglobinemia
IgA deficiency
Common variable immunodeficiency

Question 14

Selective IgA deficiency

Answer 14

Usually no symptoms, it is the most common. May have recurrent infections, allergies, or autoimmune diseases.

Question 15

What is the structure of IgA?

Answer 15

In the secretory form, the form found in secretions it is in polymers of 2-4 IgA monomers.
- there are 2 chains: J chain and secretory component.
J chain - joins the different IgA monomers.
Secretory component - produced by the epithelial cells and is also involved in joining the IgA monomers. It ensures that the IgA isn’t degraded in the mucosa.

Question 16

Agammaglobinemia

Answer 16

Defect in Bruton Tyrosine Kinase, which results in pre-B cell arrest.

• absence or markedly reduced Igs
• almost no B cells
• usually X linked but can be recessive
• treated with IV or subQ Igs

Question 17

Bruton tyrosine kinase

Answer 17

Enzyme defective in Agammaglobinemia

Question 18

Common variable immunodeficiency

Answer 18

Serum Igs are low but B cell numbers are normal.

• unclear genetic pattern of inheritance
• usually doesn’t take hold till later in life -20-30s
• treat with IV or subQ Ig

Question 19

Phagocytic disorders

Answer 19

Chronic granulotmatus disease

Chediak-Higashi syndrome

Question 20

CGD

Answer 20

X linked but can be recessive

• mutations in genes that cause deficiency in phagocyte oxidase complex and leads to defect in superoxide production.
• recurrent life-threatening infections with bacteria, fungi that cause tissue granuloma formation
• usually pulmonary, cutaneous, lymphatic, and hepatic infections

Question 21

Chediak-higashi syndrome

Answer 21

Recessive

• defect In protein that transports materials to lysosomes
• large abnormal granules in neutrophils, melanocytes, hair, Schwann cells, CNS.
• recurrent cutaneous and sino-pulmonary infections.
• albinism, mental retardation, neuropathy

Question 22

What unique thing do you evaluate for in each of the different types of deficiencies?

Answer 22

T cells - PPD, T cell subsets, HIV serology
B cells - quantitative Igs, pre and post vaccination titers
Phagocytic - peripheral smear, neutrophil oxidative burst test
Complement - total complement level CH50, complement component levels

Question 23

Primary immunodeficiency

Answer 23

When the immune system is unable to defend against pathogens in the environment.

• not acquired like HIV, chemo etc
• due to genetics
• immune system is hampered or absent