Immunity in pregnancy,
ontogenesis of immunity
Uterine mechanisms of fetus protection
against mother´s immune system
• Majority of cells does not cross placental barrier.
• No classical HLA- antigens are expressed on
trophoblast.
• Non classical HLA-G antigens protect trophoblast
cells from NK cells. Their presentation of antigens
probably leads to suppression of speciphic
immune response.
• CD46 on the surface of trophoblast cleaves C3b.
Maternal mechanisms protection fetus
from the immune system attack
• Mother is in Th2 predominance
• Possible immunosuppressive effects of
HCG, high serum levels of progesterone,
alfa-feto protein
• Partial block of lymph nodes draining the
uterus
Serum immunoglobulin levels in preand
postnatal period
Immune system in infancy
• IgG is actively transferred though the placenta ,
protective IgG, but also autoantibodies. Gradual
increase of own production of IgG
• IgM may be produced by the fetus in the late pregnancy,
does not cross the placenta
• IgA produced by the newborn, in secretions in almost
normal levels.
• T lymphocyte function – almost normal
• Nonspecific immunity- function of granulocytes,
complement system – mildly decrease in the first year of
life.
Immune system-lelated diseases
in infancy and childhood
• Increased susceptibility to infectious
diseases.
• Clinical course of infections is usually mild.
• Exception – severe course of infections
caused by encapsulated bacteria during
first two years.
• Atopic diseases usually begin in early
childhood.
• Autoimmune diseases are relatively rare.
Immune systém-related
diseases in adulthood
• Infectious diseases are infrequent, but
may be severe in course.
• Autoimmune diseases typically begin in
early adulthood.
• High prevalence of allergic diseases
continues from childhood
Immunity in seniors
• Weak primary immune response, secondary
immune response is usually normal.
• Decrease in lymphocytes, mainly CD4+
• Serum immunoglobulin levels are usually
increased.
• Immune response is generally decreased,
clinical symptoms of infection are milder
than in young persons.
• Disturbed regulation of the immune system
leads to frequent occurrence of
autoantibodies and paraproteins, but this
does not lead to clinical diseases.