anti d or anti rh antibody is formed in body after exposure to rh antigen as u see in erythroblastosis featilis while ABO antibodies have already formed since birth.why does anti RH antibody needs exposure to be formed.
Robert is correct, B+ If the blood agglutinates with anti-B antibodies then there must be type B receptors on the surface of those blood cells for the anti-B antibodies to attach to, ergo the blood is type B blood. Same reasoning for Rh.
What I've read is that it is believed that bacteria that we are exposed often have similar groups to the A and B antigens on RBCs. It seems to be protective against these infectious agents. Rh is just something we don't normally encounter in bacteria or otherwise. The usual case is either a wrong transfusion or in Rh neg mom with a Rh positive baby and during birth blood mixes and anti-Rh antibodies are formed. So for both we required exposure but with Rh the exposure must be due to human blood.
Abo blood typing are preformed. Rh blood typing needs an exposure before any reaction occurs.. why is this so? The mother's blood usually is an Rh- blood type, however if she had a Rh+ child which was inherited to the father's, then an anti- Rh agglutinin is developed from exposure to the baby's Rh antigen. In turn, when the mother got pregnant again, she already has an antiRh- agglutinin, which will diffuse through the placenta into the fetus and cause agglutination.. Rh- blood type is innate to the mother's and it needs an exposure before any reaction/agglutination will occur, unlike in ABO blood types which is already preformed. Thus, blood typing is very important in blood transfusion in order to avoid any reaction/agglutination which could be fatal.
