7. Immunity and Disease Flashcards
(143 cards)
Define an immune deficiency
Impairment in parts, or the function of specific parts, of the immune system that, in having this impairment, causes the animal to be susceptible to infectious disease.
What is a primary immune deficiency
Inherited or congenital
Occurs when there is a mutation in a gene that is associated with the immune response
What is a secondary immune deficiency and what are the common causes
Normal immune system until a physiological or pathological change occurs within the immune system
Causes - age, chronic disease, infection, therapeutics
Give 2 examples of primary immune deficiency diseases
SCID - severe combined immunodeficiency
CLAD - Canine leukocytic adhesion deficiency
What 2 dog breeds and one horse breed get SCID, and what does the mutation affect
Basset Hound - mutation for key cytokines
Jack Russel Terrier - mutation for lymphocyte formation
Arabian horse - Mutation impacts T and B cell receptor
which dog breed is CLAD common in
Irish setters
What does CLAD do to the body
Abnormal blood clotting and impair immune system
Prevents white blood cells adhering/eliminating pathogens
Give 4 examples of secondary immune deficiencies
Age-related decline - decline in CD4+
Specific infections disease - e.g. FIV
Chronic stress
Malnutrition
Why does chronic stress cause secondary immune deficiency
Glucocorticoids suppress the immune system
Why does malnutrition cause secondary immune deficiencies
reduced leptin => reduced T lymphocyte function
what is type I hypersensitivity
Immediate hypersensitivity reaction
IgE antibodies bound to mast cells
Phase 1 - sensitisation phase
Phase 2 - re-exposure phase
Explain sensitisation phase of type 1 hypersensitivity
Allergen exposure
Antigen-presenting cells capture antigens
Naive helper cells differentiate to T helper 2
Release cytokines
B cell proliferation
IgE binds to mast cells
Relocate to where allergen was first encountered
Explain re-exposure phase of type 1 hypersensitivity
Same allergen encountered
Primed IgE coated mast cells bind to antigen of allergen
Release of cytoplasmic granules
Breakdown of mast cells
Immediate hypersensitivity
Give 2 examples of type 1 hypersensitivity
Anaphylaxis
Atopic dermatitis
What is type 2 hypersensitivity
Antibody-mediated cytotoxicity
Mediated by antibodies, activates classical complement pathway
IgG antibodies travelling in the blood
Give an example of type 2 hypersensitivity
Myasthenia Gravis
What is type 3 hypersensitivity
Immune complex hypersensitivity
Formation of immune complexes and activation of the complement system
What are the two subtypes of type 3 hypersensitivities
Antibody excess (lots of IgG)
Antigen excess (less IgG but lots of antigens)
Give 2 examples of type 3 hypersensitivity
Equine recurrent airway obstruction
Canine blue eye
What is type 4 hypersensitivity
Cell-mediated, not antibody
Prolonged onset
Sensitisation and re-exposure phases
Interferon gamma and chemokine to site of presentation, recruitment of macrophages, CD4+/8+ and granulocytes
Give an example of type 4 hypersensitivity
TB skin test in cows
What lab tests are used to detect viruses
Immunodiagnostics e.g. ELISA
Culture
PCR
What lab tests are used to detect bacteria
Culture
PCR
name 2 animal side tests which are used to detect pathogens
Lateral flow
Latex agglutination tests