Immunodeficiency Diseases

Question 1

What was the first primary immunodeficiency disease to be described?

Answer 1

Bruton agammaglobulinemia

Question 2

T/F. Primary or congenital immunodeficiencies are genetic defects that result in increased susceptibility to infection that mainfest in infancy or childhood.

Answer 2

True.

Question 3

How do secondary or acquired immunodeficiencies develop?

Answer 3

as a consequence of:

• malnutrition
• disseminated cancer
• treatment with immunosuppressive drugs, or
• infection of cells of the immune system.

Question 4

What is essential for defense against infectious organisms and their toxic products?

Answer 4

integrity of the immune system

Question 5

___-___ receptors are conserved across widely diverse species, therefore any ___ -___-___ mutation affecting a TLR has negative consequences for survival.

Answer 5

Toll-like; loss-of-function

Question 6

What is the principal consequence of an immunodeficiency?

Answer 6

an increased susceptibility to infection. The nature of the infection in a particular patient depends largely on the component of the immune system that is defective.

Question 7

The types of ___ infections can predict the type of immunodeficiency.

Answer 7

recurring

Question 8

Deficient ___ immunity usually results in increased susceptibility to infection by pyogenic bacteria.

Answer 8

humoral

Question 9

What is another name for Bruton’s Agammaglobulinemia?

Answer 9

X-linked Agammaglobulinemia (XLA)

Question 10

In XLA, all ___ isotypes are very low and circulating ___ cells are absent. Pre-B cells are reduced in the ___ ___. Tonsils and lymph nodes are small and rarely palpable because there is an absence of ___ centers. However, the ___ architecture is normal.

Answer 10

antibody; B; bone marrow; germinal; thymus

Question 11

Most boys afflicted with XLA remain well during first 6 to 9 months of life, why?

Answer 11

maternally transmitted IgG antibodies

Afterwards they repeatedly acquire infections with extracellular pyogenic organisms.

Question 12

Explain the genetic defect associated with XLA.

Answer 12

loss of function of Bruton Tyrosine Kinase that is important for pre-B cell expansion and maturation into Ig-expressing B cells.

Question 13

XLA has low serum Ig___, Ig___, and Ig___ but markedly elevated concentrations of Ig___.

Answer 13

G; A; E; M

Question 14

What do patients with XLA and hyper-IgM have in common?

Answer 14

they may become symptomatic during the first or second year of life with recurrent pyogenic infections.

Question 15

What is different between XLA and hyper-IgM patients?

Answer 15

hyper-IgM patients have lymphoid hyperplasia

Question 16

Why are B cells not signaled by T cells to undergo isotype switching, which means they only produce IgM?

Answer 16

XLA’s defect is associated with the loss of function of CD40 ligand that is expressed on helper T cells. The loss of this molecule prevents the T cell from co-stimulating antigen-specific B cells through CD40.

Question 17

What is the routine treatment for humoral immunodeficiencies?

Answer 17

prophylactic antibiotics and/or gamma-globulin therapy

Question 18

Deficient ___-___ immunity usually results in increased susceptibility to viruses and other intracellular pathogens.

Answer 18

cell-mediated

Question 19

T/F. Patients with deficient T cell responses also receive routine prophylactic antibiotics and/or gamma-globulin therapy.

Answer 19

False, there are few if any treatments for defects associated with deficient T cell responses. It is rare that patients with absolute defects in T-cell function survive beyond infancy or childhood.

Question 20

In what disease does the thymus not develop?

Answer 20

DiGeorge’s syndrome

Question 21

___ ___ results from defects in morphogenesis of the ___ and ___ pharyngeal pouches during early embryogenesis.

Answer 21

Thymic hypoplasia; 3rd; 4th

Question 22

Patients with DiGeorge’s syndrome have low T cells and increased B cells but most infants die from CV defects or seizures. Those that survive infancy suffer from mental retardation. What other disease is clinically similar?

Answer 22

fetal alcohol syndrome

Question 23

What immunodeficiency disease is a rare, fatal syndrome characterized by profound deficiencies of T and B cell function?

Answer 23

X-linked Recessive Severe Combined Immunodeficiency Disease (SCID)

Question 24

In addition to having persistent infections with opportunistic organisms, what other condition are SCID patients at risk for?

Answer 24

Graft-vs-Host disease because they lack the ability to reject foreign tissue (this can also occur while in utero if mom’s T cells cross the placenta of SCID embryos)

Question 25

XSCID patients have few or no ___ and ___ cells but they usually have elevated ___ cells, however they do not produce Ig normally even after T-cell reconstitution by bone marrow transplantation.

Answer 25

T; NK; B

Question 26

What are the two aims of immunodeficiency disease treatments?

Answer 26

1. minimize and control infections

2. replace the defective or absent component of the immune system by adoptive transfer and/or transplantation.

Question 27

In addition to passive immunization with pooled gamma globulin, what is the treatment of choice for various immunodeficiency diseases?

Answer 27

bone marrow transplant

Question 28

Considering the structure of HIV, what receptor protein, if missing, can reduce an individuals chances of contracting the disease?

Answer 28

chemokine receptor

Question 29

What are some examples of the cellular reservoirs of HIV?

Answer 29

activated CD4+ T cells
Macrophages
Resting/memory CD4+ T cells

Question 30

Under what condition is a patient clinically diagnosed with AIDS?

Answer 30

they is destruction of lymphoid tissue and depletion of CD4+ T cells.