I don’t know anything about this topic, but AB+ is known as the “universal recipient”; they can receive blood donated from any type.
.
However...AB- blood type is the most rare type there is. It’s also known as the “universal donor”; they can give AB- blood to anyone, to save their life. I think there’s some deep symbolism here. Makes sense Christ is this type.
AB- is NOT the "universal donor" O is the universal donor.
Someone with AB+ is the universal RECEIVER and can receive blood from O, A, B, and AB as their blood contains all of these.
O was the first blood type and everyone has it.
so:
A can receive from A and O but only donate to A
B can receive from B and O but only donate to B
O can receive from O but can donate to A, B, AB and O
AB can receive from O, A, B, and AB but only donate to AB