Immunodeficiency Syndromes Flashcards
Defects in T cell function predispose host to IC (viral) infections. True or false?
True
What do defects in B cell function and Ig production predispose animals to?
EC bacterial disease
Why are combined immunodeficiences severe?
Because affected animals lack resistance to ALL infectious agents
What is the difference between congenital and acquired immunodeficiencies?
Congenital (primary) affects the innate and adaptive immune system and is genetic.
Acquired (secondary) is cause by microbial infections.
How are genetic disorders inherited?
Autosomal recessive inheritance happens when parents carry the gene defect.
X-Linked inheritance occurs as a result of mutations in the X chromosome.
The is no male to male transmission in X-linked inheritance. True or false?
True
Leukocyte adhesion deficiency type I- innate or adaptive disorder?
innate, autosomal
What molecule is affected in leukocyte adhesion deficiency type I and why is this critical?
CD18 becomes non-functional.
CD18 is the integrin critical for leukocyte adhesion and migration into the tissues, when it is non-functional leukocytes cannot migrate to site of infection.
What are Bovine LAD and Canine LAD?
leukocyte adhesion deficiency type I affecting cattle and dogs
What molecule is affected in leukocyte adhesion deficiency type II and why is this critical?
Defect is in L-selectin.
Selectin molecules interact with leukocytes to slow them down to allow them to migrate into infected tissues.
Chediak-Higashi syndrome- innate or adaptive disease?
innate, autosomal
What molecule is affected in Chediak-Higashi syndrome and why is this critical?
LYST is affected
Prevents lysosome from fusing to phagosome containing trapped pathogen.
What cells are affected by Chediak-Higashi syndrome?
neutrophils, macrophages, DCs, NK cells, cytotoxic T cells, etc
What species are most affected by Chediak-Higashi syndrome?
cats and cattle
What are the consequences of Chediak-Higashi syndrome?
susceptibility to diseases and early death
What is the affected molecule in Chronic granulomatous disease and why is it critical? Innate or adaptive?
Innate
Phagocyte oxidase complex Phox-19 affected. Prevents the phagoytes from making reactive oxygen species making them useless because that is their killing mechism.
What is affected in TLR signaling defects?
CD40
PAMPs cannot be sensed, resulting in host being unable to signal the rest of the body that there is an active infection
Complement deficiences make up what percentage of all primary immunodeficiencies?
1-10%
What is affected in complement defiencies?
C5-C9, meaning MAC is not successfully assembled
What cells are effected by SCID?
T-cells, B-cells, and NK cells
What does SCID result in?
very low circulating lymphocytes
failure to synthesize Igs
hypoplasia of lymphoid tissues due to lack of Ig
What is defective in SCID?
autosomal: defect in Protein Kinase (DNA-PKcs)
X-linked (XSCID): defect in gamma chain of IL-2Ry
What is the result of XSCID?
Decreased T-cells and NK cells
Normal number of B-cells with decreased function
What is the result of autosomal SCID?
Decreased number of T and B cells
End result failure of VDJ recombination, no BCR diversity
What is CVID?
Common Variable ID
What is mutated in CVID? What does this affect?
ICOS and TACI
Affects the ability to produce gammaglobulins
How does CVID affect B-cells?
Lack of blood cells in blood, bone marrow, or spleen
What animals are usually affected by CVID?
> 3 yo horses
miniature dachshunds
SCID- innate or adaptive?
adaptive
CVID- innate or adaptive?
adaptive
Hyper-IgM syndrome- innate or adaptive
adaptive
Agammaglobulinemic- innate or adaptive?
adaptive
Thymic hypoplasia- innate or adaptive?
adaptive
Selective immunoglobulin deficiency- innate or adaptive?
adaptive
What is mutated in Hyper-IgM syndrome and what does it affect?
CD40, CD40L, or NEMO
Affects T-dependent B-cell activation, APC activation, and cell-mediated immunity
What is agammaglobulinemia?
B cell deficiency
What is mutated in x-linked agammaglobulinemia?
B-cell Tyrosine Kinase (BTK) gene, prevents the ability of B-cells to develp, differentiate, and activated.
What is mutated in autosomal agammaglobulinemia?
Mutations in IgM heavy chain resulting in inability to make functional BCR
What is used to treat CVID in humans?
Gamunex, purified gamma globulin
IgG from donated blood
What are some examples of causes of acquired IDs?
HIV
Protein-calorie malnutrition
Irradiation and chemotherapy
Cancer metastases
Immunosuppression for transplants
Removal of spleen
What cells does infectious bursal disease virus affect?
B-cells
What cells do FIV and SIV affect?
Viruses affecting T-cells, retroviruses
What cells do bovine diarrhea virus affect?
macrophages
What cells do porcine reproductive and respiratory syndrome virus affect?
Macrogphages
Colostrum deprivation, vitamin A and D deficiency, and factors such as exercise and age can cause acquired IDs. True or false?
True
