If I mixed a a unit of type A+ blood with a unit of B+, would I now have two units of AB+, or just a big old mess? Could it be put in an AB+ human without ill effect?
Sadly, this really did keep me up last night.
A and B refer to different chains of sugars that are present on the surface of the red blood cells. A blood has the A chain, and B has the B chain. AB+ blood has both A chains and B chains present. So if you mixed A and B blood, you’d have just a mixture of A blood and B blood. B chains aren’t going to detach and move over onto the A blood cells. However, since AB people can safely receive both A and B type blood, they could also safely receive the mixture.
Oh, and the + refers to a whole other antigen. Since all three people in the OP are +, it doesn’t affect anything in this case.
Damn universal recipients.
Hang on though, wouldn’t the anti-A antibodies in the B+ blood break down the A+ blood, and the anti-B antibodies in the A+ blood break down the B+ blood?
i.e. why you can’t give A+ blood to a B+ person or B+ blood to an A+ person.
Wouldn’t it haemolyse in the bag?
My guess would be theres just not enough antibodies in either bag to fully coagulate the blood. The small amount of coagulated blood might still cause a problem tho.
If you added the blood to the patient One after another without previously mixing the blood I bet they’d be perfectly fine. The patients existing blood/plasma would dilute the antibodies below critical mass.
The thread title made me think of Dracula standing behind a bar, operating a mixer… pouring out pink frozen daiquiris…
No, mixing a unit of A blood and a unit of B blood won’t give you AB blood. Irishgirl said why.
That’s what I was thinking. Type A blood doesn’t just have A antibodies, it also has anti-B antibodies (AB blood only has the A and B antibodies, and dosn’t have any anti-antibodies.) I’m not sure how much is required before one type starts messing up another, but I wouldn’t want to risk it. If you needed to give an AB patient two units, and all you had was an A and a B, I’d wait for one to finish completly before giving the next one.
I don’t think this would be a problem:
Antibodies to non-self stuff are generally only found in the blood in tiny, tiny quantities. When the person is exposed to the antigen, a process is set off that causes the lymph nodes to make more of the right types of antibody
Therefore, although a person with type A blood will express B antigens if exposed to B type blood, and this will cause problems if type B is transfused into a person, there won’t be enough antibodies in one unit of blood to cause problems just by mixing the blood.
Aarghh! Please substitute “anti-B antibodies” for “B antigens” in that sentance. Sorry, it’s been a long day.
Units of blood, here in the U.S. anyway, are typically packed red cells. The plasma is taken off after donation. Blood group antibodies such as anti-A and anti-B are in the plasma. So in a unit of packed cells there will be a minute amount of plasma and correspondingly a minute amount of antibodies. Usually not enough to do anyone any harm during a transfusion. For a type AB person the choice would be type AB blood first, type A second, and type B third. In over fifteen years of Blood Bank I’ve never seen a bad reaction to out-of-type but compatible blood when using packed red cells.
Also anti-A and anti-B antibodies develop sometime after birth I believe and remain at significant levels throughout adulthood whether or not a person is exposed to any other blood. Sometimes antibody levels will drop with old age and can eventually become undetectable but they’re still lurking around to cause trouble if ignored.