Thursday, June 16, 2011

Hemolytic disease of the newborn

This morbid condition is the result of an immunological conflict between mother and baby them, there is a fetal antigen on red blood cells, red blood cells missing the mother.Fetal red blood cells pass into maternal circulation in the placenta and triggers the secretion of antibodies against fetal antigen. These antibodies cross the placenta into fetal circulation, where declanseata hemolysis with two major consequences for the child: anemia and hyperbilirubinemia.
Antigens involved in hemolytic disease of the newborn are mainly system and Rh blood group system ABO classic. There are other antigens (small groups) who can play the same role, but their frequency in neonatal hemolytic disease is reduced.
Antigens on red blood cells are located on the membrane fetal red blood cells and thus are easily detected by antibodies. Are natural maternal antibodies and immunity.Immune antibodies can be IgM (high molecular weight which prevents transplacental passage) and IgG (molecular weight, transplacental passage).Eritroblastoza fetal hemolytic disease of the fetus is a newborn and Rh incompatibility through.
Rh system antigens is a complex of six pairs, allele gene products: C C D D E E.
D antigen is hypothetical.
The lack of any Rh antigen system on red blood cells and the presence of maternal fetal red blood cells may trigger the immunological maternal-fetal conflict, but most involved in medical practice is antigen D.
Rh negative people do not have the D antigen on red blood cells and are homozygous (dd).People Rh antigen D positive red cells either as homozygous (dd) or as heterozygous (Dd). D antigen is expressed (phenotype may be) and is antigenic in heterozygous form.
Rh negative mother-father couple Rh positive homozygous (DD) will only have Rh-positive offspring (heterozygous-DD).
Rh negative mother-father couple Rh positive heterozygous (Dd) will have offspring: 50% Rh negative (dd) and 50% Rh positive (Dd).

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