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Enzymes open new path to universal donor blood

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Re: Enzymes open new path to universal donor blood

#21

Post by thaumasiotes »

Terr_ wrote: post #14
Terr_ wrote: post #13

Earlier quoted context omitted.

That naming is a little confusing, because if you say "blood group "A" or "B", that indicates the presence of A and B antigen structures, however "blood group H" means a lack of H. (Since almost everybody has H, it was discovered much later.) Since H is also a building-block needed for A and B to show up, it makes for fun medical-mystery plots, where a child's blood-type seems to be O and doesn't match their parents,…

P.S. IANAPhlebotomist, but if I could wave a wand to change the nomenclature, I'd make it stop relying on an implicit "nothing" state that keeps changing under us as we discover new features that are either usually-present or usually-absent. Instead patients would have a "blood code" that indicates the tested presence or absence of phenotype cellular features, and any feature not listed would be considered "not yet k…

> For example, today's AB- would become +HAB-R for "has H,A,B lacks Rhesus factor."

That's already the way A, B, and Rhesus factor work. The abbreviation for Rhesus factor is "+", but the formal terminology is "Rh+". I would have expected "H-" by analogy.

Re: Enzymes open new path to universal donor blood

#22

Post by Terr_ »

thaumasiotes wrote: post #21
Terr_ wrote: post #14

Earlier quoted context omitted.

P.S. IANAPhlebotomist, but if I could wave a wand to change the nomenclature, I'd make it stop relying on an implicit "nothing" state that keeps changing under us as we discover new features that are either usually-present or usually-absent. Instead patients would have a "blood code" that indicates the tested presence or absence of phenotype cellular features, and any feature not listed would be considered "not yet k…

> For example, today's AB- would become +HAB-R for "has H,A,B lacks Rhesus factor." That's already the way A, B, and Rhesus factor work. The abbreviation for Rhesus factor is "+", but the formal terminology is "Rh+". I would have expected "H-" by analogy.

> That's already the way A, B, and Rhesus factor work.

No, it isn't: The current ABO system is incapable of expressing "null" data (e.g. "we don't know if B antigens are present or not") and relies on implicit "no marking means false" assumption, which becomes a problem if a new/newly-important antigen feature is discovered, or if a new variation of an existing antigen is found.

For example, suppose we discover a new type Z, which is a membrane-sugar just like A and B, and logically ought to be encoded the same way. It exists in a 50/50 ratio in every existing blood-group, and it finally explains some rare but fatal transfusion problems.

Now some unconscious patient arrives at the emergency room with a wristband saying "AB+". Does that string mean they were tested for Z already, and it was absent, or does it mean there no data about whether Z is present or not? Nobody knows! Worse, if you do a test and discover no Z, then you write the same thing and have the same problem later, all because of the mistake of encoding "false" as an empty string.

Now you might say "Forget the ABO crap, require Z+ or Z- to appear as a separate item", I'll say: "I totally agree, but let's remove the ABO crap and encode all the antigens the same way to make it logically consistent and clear."

> I would have expected "H-" by analogy.

If you're thinking of another section like "A Rh+ H-", then that's close to what I'm proposing, except that it hasn't fixed the historical ambiguities of O/A/AB.

If you fix it to make things explicit and consistent, it becomes "A+ B- Rh+ H- ", and if you shorten Rh to R and group similar things together... that leads to codes like +R-HAB or -ABH+R, which are (ordering aside) what I just proposed.

Re: Enzymes open new path to universal donor blood

#23

Post by jorvi »

HPsquared wrote: post #7
TSP00N3 wrote: post #4

Long time listener, first time caller (finally made a HN account).. Anyways, can someone please explain how positive/negative plays a factor here? Rh +/- is mentioned once in the article but not discussed as far as being a donor. I was always told O- is the universal red cell donor [1]. Can anyone help explain is this enzyme fixes the +/- component in addition to the ABO component? Thanks! [1] https://www.redcrossblo…

There are three components that can cause problems with transfusions: "A", "B" and "Rhesus". A person can have any combination of those three (8 combinations). The A/B/AB/O is basically having only A, only B, both, or neither. And the +/- is whether you have the "Rhesus" component. The basic rule is that you can't introduce new components to a person who doesn't have them in their system, and will be treated as forei…

Also important to note that blood plasma is the reverse. So AB+ is universal plasma donor, and O- universal plasma receiver!

Re: Enzymes open new path to universal donor blood

#24

Post by quesera »

thaumasiotes wrote: post #20
linooma_ wrote: post #16

Earlier quoted context omitted.

> I think O is recessive Strangely, O is very common.

What's the strange part? "Recessive" and "common" are different concerns. Having five fingers per hand is recessive too.

> Having five fingers per hand is recessive too.

Fascinating, and true.

Which engenders speculation about how the world would be different if we counted in base-12. Obvious advantages to convenient divisibility aside.

Re: Enzymes open new path to universal donor blood

#25

Post by bayouborne »

downrightmike wrote: post #3

Very cool stuff! "For the first time, the new enzyme cocktails not only remove the well-described A and B antigens, but also extended variants previously not recognized as problematic for transfusion safety. We are close to being able to produce universal blood from group B donors, while there is still work to be done to convert the more complex group A blood. Our focus is now to investigate in detail if there are ad…

Cinemax's excellent 'The Knick' (about a chief surgeon at the Knickerbocker Hospital in 1900's New York) had a gut-wrenching one or two episode arc about efforts to refine transfusion techniques and why the team kept seemingly randomly ending up w/dead patients because no one had yet understood Rhesus factor proteins.

Re: Enzymes open new path to universal donor blood

#26

Post by shymaple »

Oh it is awesome progress! This discovery can be a significant step towards the development of universal donor blood. I have seen complications related to blood transfusion and its results. It has immense implications for blood transfusion safety and efficiency. I am curious to see its long term in-vivo experimental results.

Re: Enzymes open new path to universal donor blood

#27

Post by thaumasiotes »

quesera wrote: post #24
thaumasiotes wrote: post #20

Earlier quoted context omitted.

What's the strange part? "Recessive" and "common" are different concerns. Having five fingers per hand is recessive too.

> Having five fingers per hand is recessive too. Fascinating, and true. Which engenders speculation about how the world would be different if we counted in base-12. Obvious advantages to convenient divisibility aside.

It wouldn't be different at all. Mostly we did use units of twelve for everything. Why do you think there are twelve inches in a foot and twelve pence in a shilling?

Asking what the historical difference would be if we wrote our numbers in base 12 instead of, variously, 10, 12, or 20 (all historically common, and 60 is prominent too), is like asking what the historical difference would be if we wrote our words in Greek letters instead of Roman letters.

Note that it was common for people to count dozens on their hands; each hand has four non-thumb fingers with three knuckles each.

Re: Enzymes open new path to universal donor blood

#28

Post by quesera »

thaumasiotes wrote: post #27
quesera wrote: post #24

Earlier quoted context omitted.

> Having five fingers per hand is recessive too. Fascinating, and true. Which engenders speculation about how the world would be different if we counted in base-12. Obvious advantages to convenient divisibility aside.

It wouldn't be different at all. Mostly we did use units of twelve for everything. Why do you think there are twelve inches in a foot and twelve pence in a shilling? Asking what the historical difference would be if we wrote our numbers in base 12 instead of, variously, 10, 12, or 20 (all historically common, and 60 is prominent too), is like asking what the historical difference would be if we wrote our words in Gre…

Of course it would be different. I'm well aware of historical numbering systems, and their applications.

My point is that if base-12 was biologically natural, instead of more effortfully useful, there would be many differences in the way we do things -- although of course we would be mostly unaware of them, as a fish in water.

There would be no metric-vs-imperial units dichotomy, for example. (EDIT: Or at least the conflict would be different and likely lesser, ergo easier to switch)

NASA probably wouldn't have lost the $327MM Mars Climate Orbiter. And it wouldn't have cost $327MM in the first place.

In some cases, unit sizes would be different. That's the easy case. But in counting systems, 100 of some atomic thing would be 44% more than it is today. 1000 would be 73% more. 1MM would be almost triple. Given the attachment people have to round numbers, this would have implications. Some things would be bigger. Other things would be considered in different increments.

It's interesting. Not profound.

Re: Enzymes open new path to universal donor blood

#29

Post by wbl »

HPsquared wrote: post #7
TSP00N3 wrote: post #4

Long time listener, first time caller (finally made a HN account).. Anyways, can someone please explain how positive/negative plays a factor here? Rh +/- is mentioned once in the article but not discussed as far as being a donor. I was always told O- is the universal red cell donor [1]. Can anyone help explain is this enzyme fixes the +/- component in addition to the ABO component? Thanks! [1] https://www.redcrossblo…

There are three components that can cause problems with transfusions: "A", "B" and "Rhesus". A person can have any combination of those three (8 combinations). The A/B/AB/O is basically having only A, only B, both, or neither. And the +/- is whether you have the "Rhesus" component. The basic rule is that you can't introduce new components to a person who doesn't have them in their system, and will be treated as forei…

Oh there are more. I think hundreds are known, but only a few populations have each one.
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