Untitled - D Ank Unlimited

hesus blood group system 623 rhesus blood group system
Rhazes.
not possessing the antigen and induce hemolytic disease of
the newborn or cause transfusion incompatibility reactions.
rhesus blood group system
Rhesus monkey erythrocyte antigens such as the D antigen
are found on the red cells of most humans who are said
to be Rh + . This blood group system was discovered by
Landsteiner et al. in the 1940s when they injected rhesus
monkey erythrocytes into rabbits and guinea pigs.
Subsequent studies showed the system to be very complex;
the rare Rh alloantigens are still not characterized biochemically.
Three closely linked pairs of alleles designated
(Dd, Cc, and Ee) are postulated at the Rh locus located on
chromosome 1. The Rh system has several alloantigenic
determinants. Clinically, the D antigen is the one of greatest
concern because RhD – individuals who receive RhD +
erythrocytes by transfusion may develop alloantibodies
that may lead to severe reactions with further transfusions
of RhD + blood. The D antigen also poses a problem
1. First pregnancy (initial sensitization)
RBC with RhD antigen
Maternal circulation
Placenta
Mother
Memory cell
+C
+C
1 2 3
Cc
4 5 6 7 8 9 10 1112
Cc Cc
NH 3
Cc
Cytoplasm
Cys
COOH
Membrane
in RhD – mothers who bear children with RhD + red cells
inherited from their fathers. The entrance of fetal erythrocytes
into the maternal circulation at parturition or trauma
during the pregnancy (such as in amniocentesis) can lead to
alloimmunization against the RhD antigen that may cause
Ee
Schematic representation of Cc, Ee, and Dd polypeptide topoloty within the
erythrocyte membrane. There are twelve membrane-spanning domains and
cytoplasmic N- and C-termini. The linear diagram depicts probable sites of
palmitoylation (Cys-Leu-Pro motifs).
2. Second and third pregnancy (2° and 3° sensitizations)
Hemolysis
Mechanism of hemolytic disease of the newborn.
IgG
Memory cell
Plasma cell
R