Immune system ontogeny and neonatal immunity Flashcards
What can be found on the surface of B cells by day 60 of the calf in utero?
blood smIgM
By day 100 what can in utero calves make antibodies for?
- anaplasma
- leptospira
- parainfluenza
- rotavirus
- parvovirus
By day 200, what can in utero calves respond to?
campylobacter
chlamidya
e.coli
What is the significance of serum Ig at birth?
- normally born without serum Ig
- serum Ig at birth suggests in utero infection
What type of placenta do humans and primates have and what does it allow?
haemochorial placenta
- IgG can very easily pass through chorionic epithelium
- Babies born with same levels of - IgG as an adult does
- Via passive transfer of antibody
What type of placenta do dogs and cats have and How successfully can IgG pass?
endotheliochorial
- Not as easy for IgG to pass through both chorionic epithelium and maternal endothelium
- So less IgG at birth
- 5-10% adult level passes
What type of placenta do ruminants have and How successfully can Ig transfer
syndesmochorial
- none
- ANOTHER layer of tissue to get through (uterine connective tissue) so no Ig transfer possibl
- explains importance of colostrum in ruminants
What type of placenta do horses and pigs have and How successfully can Ig transfer?
epitheliochorial
none as uterine epithelium is ANOTHER layer to get through
What is the dominant antibody in both milk and colostrum?
IgG
What is the dominant antibody in non-ruminant milk?
IgA
When is neonatal gut permeability increased?
From 6-24 hours
In milk, where is a majority of Ig made?
mainly made locally by plasma cells in mammary gland
In colostrum, where is a majority of Ig made?
in serum
what 3 things protect colostral antibody?
- low proteolytic activity in gut
- IgA secretory component
- colostral trypsin inhibitors
What happens to complement that is absorbed by neonatals?
absorbed but non-functional
What does FnCR on enterocytes facilitate?
antibody absorption from colostrum
antibody absorption from colostrum
How are some antibodies lost from neonatals?
via neonatal glomeruli
What Ig is absorbed and what is left in the lumen in horse, pigs and ruminants
Horse and pigs - IgG/M is absorbed, IgA remains in lumen
Ruminants - all is absorbed but IgA is re-excreted back into lumen
What immune functions does colostral Ig inhibit?
- development of neonatal immune response until maternal Ig is catabolised
- meaning neonates cannot respond to vaccine until this has occured
When is the best time to vaccinate a neonate?
- must wait for maternal antibody to decline enough so that vaccination does not get wasted - but also so there is enough maternal antibodies present that it protects neonate from window of susceptibility of disease
What will failure of colostral transfer cause?
enteric disease
resp. disease
septicaemia
When is ideal puppy vaccination?
8, 12 and 16 weeks so that all puppies are able to respond as they will all have varying levels of colostral Ig
What causes of failure of colostral transfer?
- premature birth so no colostrum
- premature lactation with loss of colostrum
- poor quality colostrum
- failure to suckle
- failure to absorb
What is Primary immunodeficiency disease
- congenital (inherited)
- rare
- can be seen around 16 weeks of age
What is secondary immunodeficiency
acquired after birth and caused by natural or artificial agents
(common)
What clinical indications of immunodeficiency are there?
- chronic, recurrent infection in young, littermate animals
- infection at multiple sites
- failure to respond to standard antimicrobials
What is Weimaraner immunodeficiency syndrome
IgG deficiency
What is CLAD
canine leukocyte adhesion deficiancy (Irish setters)
What is Neonatal haemolytic anaemia
- isoimmune haemolytic anemia
- colostrum contains antibodies to neonates erythrocytes
How does neonatal haemolytic anaemia occur?
- dam sensitised to sire erythrocyte antigens
- dam has spontaneously arising antibody that cross-reacts with sire erythrocytes
What do all type B cats have?
high (conc) titred anti-A
What do some type A cats have?
low (conc) titred anti-B
What does neonatal isoerythrolysis in kittens look like?
- subclinical
- may develop tail tip necrosis 1-3 weeks post partum
How can prevention of feline NI occur?
- prevent at risk mating by blood typing sire and dam
- determine level of anti-A in dam serum before birth by titrating against sire RCs
