Blood Transfusions

[Yuqing]

I know that blood transfusions are limited amongst blood types because of anti-gen anti-body reactions. What I don't understand is how the donor's anti-body does not react with the recipient's RBCs.

For example: If a man with AB blood type received blood from an O type woman, why doesn't the anti-bodies of the O blood attack the AB blood of the man? Meanwhile, if AB is given to O, there would be a life-threatening reaction.

[mgb_phys]

There aren't any O antigens. O blood is called O because it has no A or B
So you can give O- to anybody and similairly someone who is AB+ can receive anything.

[Yuqing]

O does not have any antigens but it does have antibodies of both types. I think my question was misunderstood.

When O type blood can be given to any blood type because the recipient's antibodies will not attack the O type RBCs. Now let's think about it the other way around. Why is it that the antibodies of the O donor does not attack the RBCs of the recipient?

[Moonbear]

Unless the O donor has had a mis-matched transfusion to get exposed to AB blood, which should make them ineligible to donate blood, they'd have no antibodies to other blood types. Antibodies form AFTER an exposure.