Immunodeficiency Flashcards
In X-linked Agammaglobulinemia (XLA), ____ are usually absent
circulating B cells
In XLA, ____ are present in reduced numbers in the ____
pre-B cells; bone marrow
the defect in XLA is associated with a loss of function of ____ that is important for pre-B cell expansion and maturation into Ig-expressing B cells
Bruton Tyrosine Kinase (Btk)
characterized by very low serum IgG, IgA, and IgE, but markedly elevated concentration of polyclonal IgM
X-linked immunodeficiency with hyper-IgM
in contrast to patients with XLA, hyper-IgM patients have ____
lymphoid hyperplasia
The defect in hyper-IgM is associated with a loss of function of _____ that is expressed on helper T cells
CD40 ligand (aka CD154)
the loss of CD40 ligand prevents T cells from costimulating _____ (through CD40L)
antigen-specific B cells
because of loss of B cell costimulation, B cells are not signaled by the T cell to go through ____ and only produce ____
isotype switching; IgM
deficient ____ usually results in increased susceptibility to infection by pyogenic bacteria
humoral immunity
treatment for humoral immunodeficiency
prophylactic antibiotics and/or gamma-globulin therapy
deficient cell-mediated immunity usually results in increased susceptibility to ____ and other _____
viruses; intracellular pathogens
developmentally-related disease associated with tissue morphogenesis – the thymus does not develop
digeorge’s syndrome
Thymic hypoplasia results from defects in morphogenesis of the third and fourth ______ during early embryogenesis
pharyngeal pouches
____ is a rare, fatal syndrome characterized by profound deficiencies of T- and B-cell function; ____ is the most common form
severe combined immunodeficiency; X-linked recessive severe combined immunodeficiency disease (XSCID)
infants with XSCID have persistent infections with ____ organisms
opportunistic
infants with XSCID lack the ability to ____ and are therefore at risk for ____ which can result from maternal T cells that cross into fetal circulation while the XSCID infant is in utero
reject foreign tissue; GVHD (graft vs host disease)
XSCID patients have few/no ____ or ____, but they usually have elevated percentages of ____ (which are dysfunctional)
few/no T cells or NK cells
B cells
2 aims of current treatments for immunodeficiencies
- to minimize and control infections
2. replace defective or absent components of the immune system by adoptive transfer and/or transplantation
____ with pooled ____ is valuable for agammaglobulinemic patients and has been life saving for many with this disease
passive immunization; gamma globulin
_____ is currently the treatment of choice for various immunodeficiency diseases and has been successful in the treatment of SCID and other similar diseases
bone marrow transplantation
cellular reservoirs of HIV that contribute to plasma virus
- activated CD4+ T cells (most abundant in plasma virus- half life about one day)
- monocytes/macrophages (half life about 2 weeks)
- resting/memory CD4+ T cells (least abundant- half life >50 yrs)
AIDS is characterized by ____ and _____
destruction of lymphoid tissue; depletion of CD4+ T cells
