ABO blood group system

Always.

Then we move sequentially through the forward and reverse ABO and Rh typing, followed by the antibody screen.

Which is testing the patient’s plasma against known screening cells.

Right.

So the cold noise is silenced, and the warm-reacting anti-Kell becomes clearly visible on the panel.

Exactly.

And that same cold autoantibody in this scenario, an anti-IH, was also wreaking havoc on the patient's basic ABO typing.

Right.

And then in those cases, those moms usually have more than one antibody.

And so it's important to keep in mind that in the U.S., we cross-match really only for ABO and then RH status.

We're not cross-matching for the other major antigens.

which some of the other countries do do.

Like, I know we don't do it in the U.S., but, you know, it all comes down to cost, unfortunately.

And so And the other thing is, let's say I decide to do it at my hospital because I just truly think it's the right thing to do, right? And let's say my C-suite is like, okay, we're behind you, Jen.

We're going to let you match on Kel in addition to ABO and RHD for all women less than 50.

Well, what if a patient from my hospital goes to a hospital across town and they don't match, right? And so there's plenty of evidence out there, the Amigo trial for the learners.

Here is what twenty-first-century research has confirmed.

Your ABO blood type is not just a transfusion label, it is a disease map.

Type O individuals have a sixty-six percent reduction in odds of developing severe falciparum malaria.

That finding was published in the Proceedings of the National Academy of Sciences in two thousand and seven.

The modern blood classification system acknowledges forty-eight distinct blood group systems as of twenty twenty-five.

Most people know one.

The ABO system tells you what antigens sit on the surface of your red blood cells.

It does not tell you what those antigens do beyond transfusion compatibility.

So if you took it out and put it into a, a bowl, it turns into a, a rubbery clot.

Um, ABO blood groups had not yet been discovered.

Makes sense, too.

[laughs]

Right.

So it's interesting 'cause probably a lot of people reacted badly or even died after a transfusion, yet science kept going, and they got it figured out.

So in the 1900s to 1910s, they in, uh, they discovered blood typing, and that's usually credited to a guy named Karl Landsteiner who discovered the ABO blood groups in the year 1900.

That's so curious how they actually discovered that, right? I mean, that is an interesting one to figure out.