Immune deficiency

Question 1

Immune deficiency

Answer 1

impairment in parts, or the function of specific parts, of the immune system that, in having this impairment, cause the animal to be susceptible to infectious disease.

Question 2

What are the types of immune deficiency?

Answer 2

• Primary: inherited or congenital. There is a mutation in a gene that is associated with the immune response.
• Secondary: the animal had a normal immune system until a physiological or pathological change within the immune system e.g. age, chronic disease, infection, therapeutics.

Question 3

Example of primary immune deficiency

Answer 3

Canine leucocyte adhesion deficiency

• Autosomal recessive disorder
• Common in Irish Setters
• Leads to abnormal blood clotting and impaired immune system
• Prevents white bloods cells adhering to and eliminating pathogens
• Causes persistent neutrophilia
• Chances of finding this in clinic = rare

Question 4

How to recognise primary immunodeficiencies in practice

Answer 4

• Blood work
  
  • response to vaccination?
  • recurrent infection?
  • neutrophilia or lymphopenia?
• Consider breed susceptibilities
• Many markers to assess; may see lymphopenia, but this could also have other causes e.g. chronic stress

Question 5

Which species and breeds does Severe Combined Immunodeficiency affect?

Answer 5

Primary immune deficiency seen in dogs and horses.

• Basset hounds - mutation for key cytokines → immune system failure
• Jack Russell terriers - mutation for lymphocyte formation → inhibits the immune response
• Arabian horses - mutation impacts T and B cells receptors → clinical diagnosis not straightforward

Question 6

Differential diagnoses for outbreak of coughing in a group of dogs

Answer 6

• Bordetella Bronchoseptica
• Canine parainfluenza
• Canine adenovirus 2