Fetal/Neonatal

Question 1

first immune organ to develop

Answer 1

thymus

Question 2

working innate immunity in newborn

Answer 2

TLRs, neutrophils (somewhat deficient), macrophages present but immature, fewer NK cells (respond more strongly to IL-2 and IL-15)

Question 3

working adaptive immunity in newborn

Answer 3

response is Th-2 based. delayed DC1, IL-4 and IL-13 being produced by DC2. No IFN-gamma. higher lymphocyte counts

Question 4

Primate maternal antibody transfer

Answer 4

placenta = hemochorial, IgG easily transferred

Question 5

Dogs and cats maternal antibody transfer

Answer 5

Endotheliochorial, 5-10% of IgG transferred. Most through colostrum

Question 6

Farm animal maternal antibody transfer

Answer 6

Syndesmo- and epitheliochorial means no transfer of Ig’s. Entirely dependent on colostrum transfer

Question 7

How is are Ig’s absorbed in GIT

Answer 7

Ig’s bind FcRn receptor on intestinal epithelial cells, endocytosed and transferred to lacteals to reach the blood

Question 8

Duration of intestinal permeability

Answer 8

6-24 hours

Question 9

Reasons for failure of passive transport

Answer 9

production failure (premature birth, premature lactation, mares produce low quality colostrum)
ingestion failure (multiple births - not enough, poor mothering, newborn weakness, poor suckling drive, physical problems)
Absorption failure - up to 25% of foals fail to absorb enough

Question 10

Managing a failure of passive transfer

Answer 10

1. Close monitoring
2. Additional colostrum (if IgG <200mg/dL) - frozen or fresh
3. Intravenous plasma infusion

Question 11

Vaccinating neonates

Answer 11

Maternal antibodies can interfere by preventing an immune response. Vaccinate after they’ve gone or give boosters