Immunodeficiency Flashcards
immunocompromised
animals susceptible to infectious agents that often don’t cause disease in most animals
immunodeficiency
condition where immune system has been compromised to the extend that the animal becomes more susceptible to infection than most other members of its species
opportunistic pathogens/opportunists
don’t cause disease in healthy animals
may infect & cause disease in animals with impaired defenses (barrier functions, innate immunity, adaptive immunity)
Evidence for immunodeficiency (primary or secondary)
- chronic or recurring infection
- infections involving multiple body sites
- infection by opportunistic pathogens
- persistent lymphopenia or hypogammaglobulinemia
- failure to respond to vaccine
lymphopenia
significantly lower than 1000 lymphocytes per microL of blood
Classification of Immunodeficiencies
primary
secondary
primary immunodeficiency
inherited or cogenital
secondary immunodeficiency
acquired immunodeficiencies
Components of Immune System affected by immunodeficiencies
Innate immunity & Adaptive Immunity (Humoral immune deficiencies, cell-mediated immune deficiencies, severe combined immunodeficiency)
Humoral Immune Deficiency
B cells and Immunoglobulins
Cell-Mediated Immune Deficiency
T cells
Severe Combined Immunodeficiency
BOTH T and B cells are deficient
Primary Immunodeficiency present
at birth
primary immunodeficiency normally due to
genetic mutations
primary immunodeficiency features
- become apparent as maternal Abs decline
- may occur in siblings (litters)
- may affect a particular breed
- QUITE RARE
Types of Severe Combined Immunodeficiencies
- DNA-Dependent Protein Kinase (DNA-PKcs)
- common gamma-chain issue
DNA-Dependent Protein Kinase (DNA-PKcs)
SCID found in Arabian foals & related breeds (also in jack russell terriers)
-incomplete rearrangement of immunoglobulin & T-cell receptor genes =>no T or B cells
Common gamma-chain SCID
common for IL2, IL4,IL5,IL7,IL9,&IL15.
-critical failure probably b/c of defective signaling for IL7 which is needed for lymphocyte maturation
Selective IgA Deficiency
relatively common in dogs
- a relative not an absolute deficiency
- IgA below normal range but NOT absent
reason why is unknown
Immunosenescence
age-related alteration in immune system & its function
Immunosenescence effects
- fewer circulating CD4 & more CD8
- predominantly memory cells, fewer naive lymphocytes (maybe decreased ability to respond to new Ags)
- elevated IgA levels (serum & mucosal)
Pharmacologic immunodeficiency
results from use of immunosupressive drugs to treat autoimmune disease or chemotherapeutic agents to treat cancer
Infectious immunodeficiencies
caused by certain infectious agents affecting:
- certain classes of lymphocytes
- lymphoctes or WBCs in general
- damage to lymphoid tissues &/or bone marrow
Stress as a secondary immunodeficiency
stress induces it by release of higher levels of glucocorticoids from adrenal cortex.
an immune suppression
