▲ | nick238 a day ago | |||||||||||||||||||
There are 48 blood type systems, of which ABO (giving A, B, AB, and O) and Rh (+/-) can be combined to form the 8 common types. There are effectively millions of types because all the systems combined combinatorially, but most antigens beyond ABO and Rh don't cause that much of an issue, so in emergency cases, they just go with them. | ||||||||||||||||||||
▲ | gus_massa a day ago | parent | next [-] | |||||||||||||||||||
A few years ago, I made a comment in a similar topic asking for more details, and I got a very good reply. Hat tip to tait: > It's complicated. > There are more than 35 red blood cell groups (see https://www.science.org.au/curious/people-medicine/blood-typ... for a nice writeup). For each of those blood groups, there is more than one possible configuration of some protein or carbohydrate (something like more than one possible genetic sequence leading to more than one kind of molecule on the surface of the RBCs). > And, even with ABO, there can be infrequent variations that make things more complicated (see https://professionaleducation.blood.ca/en/transfusion/best-p... for more). > For the other blood groups, I think every case the groups were identified because a patient somewhere made an antibody, causing either a transfusion reaction (if not tested ahead of time) or, more likely, a positive (incompatible) reaction on in compatibility testing. > [...] It's worth reading the full original comment because it has more interesting details https://news.ycombinator.com/item?id=33507052 | ||||||||||||||||||||
▲ | hinkley a day ago | parent | prev | next [-] | |||||||||||||||||||
Is that what’s going on with organ matching? | ||||||||||||||||||||
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▲ | thaumasiotes a day ago | parent | prev [-] | |||||||||||||||||||
Why are A and B considered to belong to the same "system"? They combine with each other combinatorially in exactly the same way that rhesus factor combines with them, and presumably the same way that all other systems combine with all other systems. | ||||||||||||||||||||
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