Why Donor Blood O Doesn't Stimulate an Immune Response in Recipient A

[Cheman]

If we give someone with blood group A a transfusion using an O doner we say they are safe, since the O blood cells will not possesses antigens to stimulate an immune response in the recipient.

But surely the O doner blood with contain anti-A antibodies and memory cells that will be stimulated by the A blood cells and should surely lead to agglutination and an immune response - but this doesn't happen. Why?

Thanks in advance.

 

[gerben]

It is better to give a matching blood type, but in an emergency when the bloodtype is not known group O blood can be given, this may indeed destroy some of the recipients red blood cells. However nowadays a preparation of only red blood cells is given.

 

[quetzalcoatl9]

also, you would expect that the level of anti-A antibodies would be extremely low, probably even none for most O-type people.

An exception would possibly be a mother of O-type blood that gave birth to an A-type child, or vice versa.

 

[Monique]

Gerben is true, it is also important to understand that it's a matter of dose:

From O to A means that there are few anti-A antibodies to a lot of A type blood, only little agglutination will take place.

Some A blood to an O individual, means that there is a lot of anti-A to a little A type blood. It is now that a severe reaction will take place.

 

[Monique]

An exception would possibly be a mother of O-type blood that gave birth to an A-type child, or vice versa.

Only the rhesus factor is of concern during the second pregnancy of a Rh- mother.