Immunodeficiency Flashcards
Where can immunodeficiency occur (2)?
- at the stem cells and precursors
2. along the maturation pathways
What is primary immunodeficiency?
Genetic defects
What is secondary immunodeficiency?
Acquired or physiologic
Why are dogs and cats less severely affected by failure of passive transfer than are ruminants, horses, and pigs?
- Dogs and cats have an endothelial placenta so there is some IgG absorption in utero
- ruminants have a syndesmochorial placenta and horses and pigs have an epitheiolchorial placenta, so there is no in utero IgG transfer
What are the relative concentrations of different Igs in ruminants and non-ruminants?
ruminants- IgG»>IgM>IgA
non-ruminants- IgA»>IgG>IgM
What is the relative amount of Ig in the colostrum, serum, and milk across all species?
Colostrum»>serum»>milk
what do we see as the immune system matures and is exposed to antigens (5)?
- Expansion of lymphocyte numbers
- Shift in lymphocyte subsets
- Increased abilityof cells to respond to cytokines and proliferation
- Shift in cytokine profile (Th2 to Th1)
- Increasing concentrations of Igs in serum and mucosal surfaces
What five things can occur when a fetus/newborn is exposed to BVDV?
- Early after conception- abortion
- Early development- tolerance and persistant infection
- Later in development- fetal malformations
- Late gestation- does not negatively impact fetus
- Exposed after birth- develop classic VD
Why would an early after conception BVDV infection lead to abortion?
Infections that stimulate Th1 often result in fetal compromise or loss
How is enough tolerance maintained during pregnancy to allow pregnancy to initiate and the fetus to survive?
Often unaffected due to a strong Th2 mediated and IL10 suppressive response in the uterus
What are examples of secondary immunodeficiency not yet discussed (6)?
- Age
- Medical immunosupression
- Virus induced immunodeficiency
- Cancer
- Stress
- Malnutrition
What are these substances needed for specifically in immune function?
- zinc
- copper
- selenium
- Vitamins A and E
- T cells
- neutrophils
- most immune cells
- lymphocytes and antioxidant function
Defects in neutrophil function are most associated with ________ infections.
Bacterial
Defects in T cell function are most associated with ________ infections.
Viral
Defects in B cell function are most associated with ________ infections.
both bacterial and viral as well as fungal- so all of them apparently
Leukocyte adhesion defect of dogs and cows (CLAD and BLAD) is a defect in what molecule?
CD18- loss of integrin function
CD18 binds with what other subunits to form what?
CD11a/CD18- LFA-1
CD11b/CD18- Mac-1 (CR3)
CD11c/CD18- (CR4)
SCID stands for what?
Severe combined immunodeficiency
What breed of horses is this most commonly seen in?
Arabians
Clinically, how does SCID present?
foal that is sick, usually presenting with a secondary bacterial pneumonia (can easily get secondary infections due to the lack of T and B cells)
How is SCID diagnosed?
Lymphocyte count <1000/ul
Hypoplasia of primary and secondary lymphoid organs
Absence of IgM before nursing
How does a defect in a DNA repair enzyme lead to lack of T and B cells?
Plays a key role in TCR and BCR rearrangement
Selective IgA deficiency in dogs is most often seen in what breeds?
German Shepherds and Shar Peis
IgA deficiency is associated with what clinical presentations?
Associated with pyoderma, atopy, and furunculosis (in German Shepherds), and SI bacterial overgrowth
Degenerative IgG/ selective IgG deficiency is seen in what breeds?
Weimaraner dogs and Cavalier King Charles Spaniels (also red Danish cattle)
Juvenile llama immunodeficiency most resembles what immunodeficiency?
SCID?- repeated opportunistic infections, T and B cell depletion, depressed lymphocyte responses, and low serum IgG
