Lecture One

Question 1

What are the two different types of innate immune system deficiencies?

Answer 1

1. Abnormal phagocyte function

2. Complement deficiciency

Question 2

What are the 3 different types if adaptive immune deficiency and what causes them?

Answer 2

B-cell immunodeficiency (decreased Ig production)
T cell immunodeficiency (decreased cell mediated immunity) 
Combined immunodeficiency (B-cell and T cell; SCID)

Question 3

What is the cause of a primary immunodeficiency and when ?

Answer 3

A primary immunodeficiency is normally congenital. The clinical signs develop after the waning of maternally derived passive immunity - this is rare and is generally breed associated

Question 4

What is is meant by a secondary immune deficiency?

Answer 4

A secondary immune deficiency is one that is normally acquired

Question 5

List 2 main causes of secondary (acquired immunodeficiency):

Answer 5

Failure of passive transfer and medical intervention (chemotherapy, immunosuppressive drugs) (iatrogenic meaning caused as a result of the veterinarian)

Question 6

Which of the following species are likely to be most vulnerable to the effects out of the following and why? (ruminant, horse, pig, human dog and cat)

Answer 6

Most affected = horses, ruminant and pig - due to no maternal transfer of Ig across the placenta

Dog/cat = uncommon since placenta permits transfer of small amounts of Igs

Human = least affected as significant transfer of Ig across placenta

Question 7

What is the effect of a failure of passive transfer?

Answer 7

Individual will have a little bit of self-made Ig, but no placental transfer occurs

Question 8

What are the potential causes of passive transfer failure?

Answer 8

1. Lack of colostrum ingested by newborn ( a failure to suckle)
2. Lack of colostrum produced by dam (e.g. premature birth)
3. Absorption failure by newborn

Question 9

What are the clinical signs from failure of passive transfer?

Answer 9

Often non specific signs e.g. lethary that onsets within the first couple of days

Question 10

What are the physical examination findings from a failure of passive transfer?

Answer 10

Fever (or hypothermia), Evidence of pneumonia (increased RR and effort), evidence of umbilical infection, evidence of joint infection (lameness, swollen joints)

Question 11

What are three diagnostic tests that could be used to assess failure of passive transfer?

Answer 11

1. Measurement of IgG concentrations - using a stall-side testing kit
2. Complete blood count - abnormal white blood cell count, toxic changes in white blood cells
3. Serum biochemistry - low globulin concentrations

Question 12

How is failure of passive transfer treated?

Answer 12

IV administration of plasma containing Igs - doesn’t work 24 hours post parturition
Antibiotics to treat infection

Question 13

How can failure of passive transfer be prevented?

Answer 13

ensure that the dam is healthy and has been vaccinated and after birth verify that the foal stands and nurses

Question 14

What should the serum [IgG] be 12-18h after birth?

Answer 14

> 8g/L = adequate passive transfer
4g/L = failure of passive transfer
4-8 g/L = partial failure of passive transfer

Question 15

What is meant by the term iatrogenic immunosuppression?

Answer 15

Acquired immunodeficiency due to the result of immune suppressant medication causing secondary opportunistic infections occurring. Secondary opportunistic infections can occur due to urinary tract infection, cutaneous/skin infection, blood stream infection