Neonatal immunity (year 2) Flashcards
what is the first lymphoid structure to form?
Thymus and then secondary lymphoid organs
are the levels of circulating macrophages and neutrophils normal in the neonate?
yes but function is impaired
what impairs the function of circulating neutrophils and macrophages in the neonate?
at birth maternal hormones flood the neonate this triggers an anti-inflammatory response
what are the levels of complement like in the neonate?
low as phagocytosis and opsonisation is impaired due to the limited neutrophil and macrophage function
how do animals get maternally derived antibodies?
colostrum and placenta
how do neonates get lymphocytes?
from colostrum but their survival is questioned
how much passive immunity is transferred from placenta and colostrum in dogs/cats?
5% placental
95% colostral
how much passive immunity is transferred from placenta and colostrum in ruminate, pigs and horses?
100% colostral
describe the process by which immunoglobulins enter milk
active trader from blood under hormonal influence (oestrogen and progesterone)
what is the main antibody found in colostrum?
IgG
how does the immunoglobulin content change as colostrum turns into milk?
more IgA and less IgG
what else does colostrum contain other than immunoglobulins?
cytokines (growth factors)
other hormones
why is it essential colostrum is is ingested within the first few hours of life?
enzyme levels are low/blocked so proteins can reach the small intestine
newborns briefly have receptors for IgG present on the intestinal epithelia
what immunoglobulins are selectively absorbed in pigs/horses?
IgG and IgM
IgA stays in the intestine
how long after birth in ruminants until absorption begins to decline and then reaches nothing?
starts declining after 6 hours
no absorption by 24 hours
