Immunodeficiency Diseases Flashcards
What was the first primary immunodeficiency disease to be described?
Bruton agammaglobulinemia
T/F. Primary or congenital immunodeficiencies are genetic defects that result in increased susceptibility to infection that mainfest in infancy or childhood.
True.
How do secondary or acquired immunodeficiencies develop?
as a consequence of:
- malnutrition
- disseminated cancer
- treatment with immunosuppressive drugs, or
- infection of cells of the immune system.
What is essential for defense against infectious organisms and their toxic products?
integrity of the immune system
___-___ receptors are conserved across widely diverse species, therefore any ___ -___-___ mutation affecting a TLR has negative consequences for survival.
Toll-like; loss-of-function
What is the principal consequence of an immunodeficiency?
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.
The types of ___ infections can predict the type of immunodeficiency.
recurring
Deficient ___ immunity usually results in increased susceptibility to infection by pyogenic bacteria.
humoral
What is another name for Bruton’s Agammaglobulinemia?
X-linked Agammaglobulinemia (XLA)
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.
antibody; B; bone marrow; germinal; thymus
Most boys afflicted with XLA remain well during first 6 to 9 months of life, why?
maternally transmitted IgG antibodies
Afterwards they repeatedly acquire infections with extracellular pyogenic organisms.
Explain the genetic defect associated with XLA.
loss of function of Bruton Tyrosine Kinase that is important for pre-B cell expansion and maturation into Ig-expressing B cells.
XLA has low serum Ig___, Ig___, and Ig___ but markedly elevated concentrations of Ig___.
G; A; E; M
What do patients with XLA and hyper-IgM have in common?
they may become symptomatic during the first or second year of life with recurrent pyogenic infections.
What is different between XLA and hyper-IgM patients?
hyper-IgM patients have lymphoid hyperplasia
Why are B cells not signaled by T cells to undergo isotype switching, which means they only produce IgM?
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.
What is the routine treatment for humoral immunodeficiencies?
prophylactic antibiotics and/or gamma-globulin therapy
Deficient ___-___ immunity usually results in increased susceptibility to viruses and other intracellular pathogens.
cell-mediated
T/F. Patients with deficient T cell responses also receive routine prophylactic antibiotics and/or gamma-globulin therapy.
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.
In what disease does the thymus not develop?
DiGeorge’s syndrome
___ ___ results from defects in morphogenesis of the ___ and ___ pharyngeal pouches during early embryogenesis.
Thymic hypoplasia; 3rd; 4th
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?
fetal alcohol syndrome
What immunodeficiency disease is a rare, fatal syndrome characterized by profound deficiencies of T and B cell function?
X-linked Recessive Severe Combined Immunodeficiency Disease (SCID)
In addition to having persistent infections with opportunistic organisms, what other condition are SCID patients at risk for?
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)
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.
T; NK; B
What are the two aims of immunodeficiency disease treatments?
- minimize and control infections
2. replace the defective or absent component of the immune system by adoptive transfer and/or transplantation.
In addition to passive immunization with pooled gamma globulin, what is the treatment of choice for various immunodeficiency diseases?
bone marrow transplant
Considering the structure of HIV, what receptor protein, if missing, can reduce an individuals chances of contracting the disease?
chemokine receptor
What are some examples of the cellular reservoirs of HIV?
activated CD4+ T cells
Macrophages
Resting/memory CD4+ T cells
Under what condition is a patient clinically diagnosed with AIDS?
they is destruction of lymphoid tissue and depletion of CD4+ T cells.
