Secondary Immunodeficiencies Flashcards
immunocompromised
altered physiology of the immune system
immunosuppressed
exogenous factor dampening the immune system
immunodeficiency
missing or malfunctioning component of the immune system
how does an immunodeficiency present
- recurrent or chronic infections
- neoplasia
- decreased vaccine response
will a deficient innate or adaptive immune system cause more rapid fatality
innate - no ability to control pathogen or activate the adaptive immune system
deficient adaptive immune system will cause slower progression of disease because the innate system can provide some protection
primary immunodeficiency
inherited condition (hereditary, genetic, congenital)
PERMANENT - encoded into the animals DNA
animal is BORN with deficient immune system - age of onset is YOUNG
- may vary w/ maternal antibodies
secondary immunodeficiency
acquired - viral vs. non-viral
can be transient OR permanent - NOT encoded into animal’s genome
animal is born with a normal immune system - age of onset is variable; can be older
is primary or secondary immunodeficiency more common
secondary
what are viral causes of secondary immunodeficiency
retroviruses, parvovirus, panleukopenia, distemper, many chicken viruses
what are non-viral causes of secondary immunodeficiency
failure of passive transfer
malnutrition
stress
age
toxins
drugs
endocrine disease
feline immunodeficiency virus (FIV)
retrovirus that targets CD4 T cells
- integrates into genome and becomes latent for long period of time
- causes GRADUAL destruction of CD4 T cells
- end stage disease: latent virus reactivates and causes RAPID destruction of T cells
do most cats make it to end stage FIV
no - most will develop neoplasia or opportunistic infections and die before reaching end stage FIV
what is unique about CD8 T cells of FIV infected cats
often much higher CD8 T cells than healthy cats
canine parvovirus & feline panleukopenia virus
virus that targets rapidly dividing cells
- affects puppies and kittens once maternal antibodies wean
what are the targets and outcomes of parvovirus/panleukopenia virus
crypts of intestinal epithelial cells, lymphoid tissue, bone marrow, and thymus
causes SEVERE lymphopenia despite high demand for CD8 T cells
BM infection causes neutropenia
what is the most common sequelae to parvo/panleuk infections and how do you prevent it
sepsis - caused by secondary bacterial infections
treat prophylactically with antibiotics
infectious bursal disease virus
“gumboro disease”
virus that targets B cells of the bursa
- primarily B lymphoblasts and IgM lymphocytes
affects chicks ages 3-6 weeks
- period of maximum development of bursa
what lesion does infectious bursa disease virus cause
hemorrhagic and edematous bursa
leading to increased susceptibility to opportunistic bacterial infections
does infectious bursa disease virus affect circulating B cells
no - only B cells in the bursa
does not affect stem cells either
marek’s disease
herpesvirus that targets:
- early: phagocytes and respiratory epithelium
- late: lymphocytes in bursa, thymus, and spleen
establishes latency in CD4 T cells - when re-activated, will replicate oncogene
early signs of marek’s disease
targets phagocytes and respiratory epithelium
causes IMMUNOSUPPRESSION
late signs of marek’s disease
targets lymphocytes
reactivation of virus within CD4 T cells leads to replication of viral oncogene leading to LYMPHOMA
failure of passive transfer
inadequate Ig transfer from dam to fetus
caused by poor quantity/quality of colostrum Ig, ingestion, or absorption
how do you detect FPT
serum IgG of fetal blood
can also measure milk but does not definitively determine FPT because it might have been an ingestion/absorption problem
what are common outcomes of FPT
- septicemia
- septic arthritis
- pneumonia
- enteritis
how does malnutrition cause immunodeficiencies
stress (anorexia), poor quality diet, and specific nutrient deficiencies cause inadequate immune response
- calories are required for neutrophil function
- vitamin A, iron, zinc, copper, selenium required for immune response
how does stress cause immunodeficiencies
leads to decreased T cell responses, NK cell activity, and IL-2 production
what are examples of stress for cattle, cats, and horses
cattle: shipping
cats: vet visits, new animal introduction
horses: performance/racing
what endocrine diseases are often associated with decreased immune function
hyperadrenocorticism:
- excess cortisol
- neutrophilic but decreased function of neutrophils
- decreased lymphocyte and macrophage function
- decreased Ig
diabetes:
- decreased CD8 T cell and neutrophil function
- predisposes to glucosuria
how does age affect immunodeficiencies
immune system changes with age
in normal, healthy cells: if cell senses oncogenic stressors it will begin secreting factors to induce apoptosis to prevent the spread of disease
aging causes immunosenescence and inflammaging
aging also causes decreased innate and memory responses
immunosenescence
decreased ability of macrophages to clear senescent cells leading to accumulation of those cells
occurs as the immune system ages
inflammaging
macrophage driven increase in chronic, low level inflammation seen in older animals
what toxins often lead to immunodeficiency
insecticides, herbicides, fungicides, heavy metals, mycotoxins
what drugs cause immunodeficiency
glucocorticoids
chemotherapy
high estrogen doses
