[HN Gopher] Lab-grown blood given to people in world-first clini...
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Lab-grown blood given to people in world-first clinical trial
Author : sohkamyung
Score : 411 points
Date : 2022-11-07 05:16 UTC (17 hours ago)
(HTM) web link (www.bbc.com)
(TXT) w3m dump (www.bbc.com)
| inportb wrote:
| This appears to be a transfusion of mature blood cells derived
| from donor CD34+ hematopoietic stem cells, and it sounds like
| they're able to collect usable numbers of stem cells from a
| regular unit of whole blood... but _how?_
|
| People normally don't have a whole lot of stem cells in the
| peripheral circulation (if they did, they'd have leukemia). For
| the purpose of stem cell transplantation, the donor is given
| medications to mobilize stem cells from the bone marrow before
| collection. I'm sure they're present in very small numbers in the
| blood, and perhaps they could be cultured in the lab, but even
| stem cells become exhausted eventually. This is the innovation,
| probably.
| tait wrote:
| The number of circulating CD34+ cells varies by individual, and
| by age.
|
| I volunteered for an unstimulated collection when we were
| validating the process of stem cell collection at my work. I
| was at the upper limit of normal, but I technically had enough
| in CD34+ cells in my circulation to do a transplant even
| without stimulation, and I was in my early 30s at the time.
|
| A single CD34+ cell can probably make a lot of RBCs. (Ok, to be
| pedantic, I'm not 100 percent sure they are really CD34+ cells,
| I was taught that CD34+ is a marker for myeloblasts, and the
| cell population you would probably want are the CD34-
| hematogones as they are self-replenishing. The article didn't
| seem to say either way).
| chatterhead wrote:
| nelox wrote:
| Am4TIfIsER0ppos wrote:
| A nice way to undercut my market of "pay me". Although maybe this
| will set a price floor above 0 for blood.
| clintonb wrote:
| I wonder how long it will take for the technology to reach the
| point where it's used for performance enhancement in sports. For
| example, if these red blood cells can hold a bit more oxygen,
| that's an advantage for an endurance athlete.
| Gatsky wrote:
| Athletes already do this - they collect their own blood and
| store it and then transfuse themselves to supranormal levels
| prior to their sporting event. Lance Armstrong did this.
|
| Lab grown blood would make this a bit more convenient, albeit
| at astronomical cost.
| fbdab103 wrote:
| I assumed the reason to use their own blood was to avoid
| detection. Presumably synthetic blood is weird enough that it
| becomes trivial to detect its presence that would make it a
| no-go for cheating.
| blackoil wrote:
| Till you start modifying the body to produce these
| supercells.
| akiselev wrote:
| "Synthetic" in this case doesn't mean that it's made using
| an alternative chemical process - it just means they're not
| made in bone marrow.
|
| This process filters out stem cells from a blood donation
| and prevents them from becoming red blood cells long enough
| to multiply them significantly.
| Gatsky wrote:
| Yes. Some of the proteins in the cells would be different
| to the host cells, due to the exogenous stem cell source.
| This might be detectable with mass spectrometry (protein
| sequencing is otherwise difficult and laborious). There
| might also be different post translational modifications
| on the lab cells.
| clintonb wrote:
| True. I imagine a scenario where the athlete is given
| supranormal blood without the extra step of collecting from
| themselves.
|
| This is just me speaking "out loud". Today, this would be
| quite expensive. I can see a future where the technology
| scales and the richer teams/individuals try this out.
| ip26 wrote:
| The salient point is it's prohibited in sports where it
| gives you a boost, and there are already ways to do it
| today.
| ChrisKnott wrote:
| Nowadays they just take EPO
| casefields wrote:
| Lance Armstrong was busted for blood doping. The cutting edge
| is way beyond that.
| olddustytrail wrote:
| > It is hoped the lab-grown blood will be more potent than
| normal.
|
| Interesting. I've been expecting artificial blood for a while but
| hadn't considered this angle. Athletes and the wealthy with
| better performance blood!
| nathias wrote:
| get ready for "I drain my blood and replace it with synthetic
| every morning to increase coding efficiency" hn posts in a year
| or two ...
| bdg wrote:
| Blood is highly complicated.
|
| I think the HN audience understands it at a level of "blood is
| red cells, white cells, and platelets", but that's really not the
| whole picture. Blood also has plasma which is composed of gas,
| nutrients, proteins, ions, and water. We can actually refine
| blood plasma down to a state where it's basically 100% safe even
| if someone with "bad blood" donated it.
|
| These 4 different blood components all get seperated at the lab,
| frozen for storage, and turned into individual products which can
| be mixed+matched depending on medical need.
|
| Don't get me wrong, growing red cells in a lab is awesome, but I
| don't see it the same way a lot of comments in this thread do
| (solving a storage issue, saving a lot of lives, etc).
|
| I think the realistic applications of lab-grown-blood over the
| next 15 years will be closer to treating rare diseases or
| possibly rare blood types (some people exist outside the typical
| A, B, AB, O groupings). I don't see this fixing logistics or
| supply/demand issues in the next 15 years, especially with how
| highly regulated the blood supply is in any first world nation.
| WeylandYutani wrote:
| Don't homeless people in America sell their blood for money?
| Was a bit of a scandal when it ended up in my country. Might as
| well buy organs from the Chinese lol.
| pkaye wrote:
| US is one of the 5 countries (US, Germany, Austria, Hungary
| and Czesh Republic) that pays for plasma donations. It
| represents 60%+ of plasma donations worldwide. Most other
| countries other than the 5 don't sufficiently produce plasma
| domestically to supply their needs and must import it. It
| appears some compensation is needed for people to donations
| sufficiently. The Plasma is broken down it various components
| used to treat all types of diseases. During the pandemic
| there were all kinds of worldwide shortages of plasma
| products because US plasma donations went down. Other
| countries should reconsider their approach to plasma
| donations to reduce risks of shortages.
|
| https://www.euractiv.com/section/health-consumers/news/us-
| bl...
| CapitalistCartr wrote:
| Yes, plasma. I did it when I was poor(er). It's hard as we
| age, but it pays.
| kulahan wrote:
| I did this when I was young. I used to joke that all my
| furniture was paid for with "blood money". Years later I
| read a report that there were some negative side-effects
| being discovered for people who donated for very long
| periods of time, so I guess I'm glad I stopped. Looking
| back, the idea of selling body parts, even if it's "just
| plasma" still feels icky to me.
| cguess wrote:
| You can donate plasma for money, yes. It's not just homeless
| people, rarely it is. College students trying to make
| drinking money and such are very common. It's considered less
| exploitative because the cells are pumped back in, with just
| the plasma being kept for later use.
|
| You cannot sell whole blood donations though by law, that's
| all volunteer.
| cookieswumchorr wrote:
| the application i immediately thought about is disaster
| medicine.
|
| This is when you need huge amounts of blood, and my guess is
| that it can be less perfect, when there is simply no other
| choice to save lives.
|
| An inferior substitute is better than nothing
| est31 wrote:
| What about coagulation? It is needed in situations where you
| have acute blood loss, and plasma contains the coagulation
| factors. You already probably want to give your patient
| coagulants in such a situation but I don't know if those are
| enough on their own or they need cooperation from existing
| factors in the plasma.
| kibwen wrote:
| I think it might be the opposite, actually. In a disaster,
| when you need a sudden surge of supply, you're not going to
| have time to scale up your production. Even if we had
| reliable supplies of synthetic blood, I think disasters are
| always going to call for mass donations from the old-
| fashioned blood producers.
| [deleted]
| BolexNOLA wrote:
| > I think disasters are always going to call for mass
| donations from the old-fashioned blood producers.
|
| Maybe I'm parroting an incorrect bar top factoid, but isn't
| it usually the case that they need the blood _before_ the
| disaster? That when events like 9 /11 occur and people rush
| to donate blood, it's not actually going to do much for the
| immediate problem?
| ebiester wrote:
| Yes and no. It won't do much for the immediate problem,
| but you're about to go through a lot more blood and will
| need to replenish the stores.
| tyre wrote:
| With 9/11 specifically it didn't do much for the
| immediate problem because there wasn't much need for
| blood. People crushed under the weight of the towers
| weren't bleeding out, they were just dead.
| 6stringmerc wrote:
| Yeah field work sounds great for this! Stabilize then treat.
| Good observation.
| Cthulhu_ wrote:
| That's also where blood plasma comes in, which can be donated
| once a month (as opposed to blood which is only a few times a
| year).
|
| I mean if this can be scaled up to producing gallons an hour
| in the field then sure, but we're a ways away from that
| still.
| Blikkentrekker wrote:
| > _We can actually refine blood plasma down to a state where it
| 's basically 100% safe even if someone with "bad blood" donated
| it._
|
| Do you have a source on this? Given that many blood donation
| facilities still refuse many "risk groups", which honestly
| always carried the stench of politics to me how arbitrarily
| they are selected, from donating blood?
| bdg wrote:
| I'm concerned that someone might take my previous statement
| and assume this means all blood donations are safe -- they're
| not. Without a bunch of steps in place they're horrifyingly
| risky, and our screening technology is not good enough. I'll
| explain more in a moment.
|
| To answer your direct question, in Toronto there was a doctor
| who wanted to open a pay-for-plasma clinic like they have in
| the US. In Canada, blood donations are not paid for which is
| one of the core reasons the supply is considered to be safer
| than other first world countries. The regulators shut it down
| and stopped him, not because of cleaning the plasma from the
| blood, but for policy reasons.
|
| Back to the point about safe blood... Being a person who is
| allowed to donate blood is not related to this cleaning
| process but statistics about risk and also related to costs.
| So this is part of why there are no plasma clinics in Canada.
|
| The blood donation is tested, but the tests don't catch
| everything. Really horrible diseases can test negative, which
| is why the process to donate blood includes an interview to
| categorize a high risk donor. This is why they don't let you
| donate blood when you have been living in europe for many
| years, have tattoos, multiple sexual partners, or had male-
| with-male sex. A lot of people hear about this and are
| totally outraged and jump to assumptions that the blood
| donation system is stuck in some anti-gay-rights 1900s
| puritan mindset, but that's not what's going on.
|
| People regularly walk into blood donor clinics, lie about
| their high risk factors because they want to "prove a point",
| the tests for things like HIV can't always catch it all the
| time (especially in early stages; stages where there are no
| symptoms), and one blood donation could actually make it to
| several other people (like a baby, a motorcycle accident
| victim, and a surgery patient). It happens regularly enough
| that your nation's blood supply has a "lookback/traceback"
| program where they have 10-100 people who sit there all day
| working on cases and sending letters to people who received
| bad blood, and it can even come up 5+ years later when
| someone who donated blood in 2015 just got a diagnosis in
| 2020, all those people in the "bloodline" get notified,
| banned from the system, and advised to get tested too.
|
| Doctors depend on multiple layers of checks to keep the blood
| supply clean, one of them is a statistical layer, one is a
| testing layer, one is the processing to keep the blood
| clean/safe, another is policy. Please don't interpret my
| point about plasma being highly cleanable to mean that all
| blood components in general can be safely received from the
| homeless.
| Blikkentrekker wrote:
| So, what I'm to take from this is that though plasma itself
| can be donated without risk, the other components cannot?
| tait wrote:
| Plasma undergoes extensive processing that inactivates
| many viruses that would not be inactivated by current
| blood processing. See https://www.pptaglobal.org/safety-
| quality/pathogen-safety
| bearmode wrote:
| There is a LOT more to blood! There are a total of 36 different
| blood group systems, with the most important being the ABO
| group that everyone knows gives you your A, B, O, or AB blood,
| and the (RHD gene of the) Rh group that gives you the + or -
| part of it.
|
| When given a single transfusion, a patient can usually be given
| blood based on the ABO and +/- part of the Rh groups alone, but
| there's more to the Rh system than most people know.
|
| As well as the RHD gene, there's also the RHCE gene. The RHD
| gene can either be present (D, gives you positive blood) or not
| present (d, gives you negative blood), but the RHCE gene can
| give you one of four variations of the C, c, E and e antigens.
| When the two genes combine, you can have any of the following
| combinations: Dce, DCe, DcE, DCE, dce, dCe, dcE, dCE (which
| were given simplified names: Ro, R1, R2, Rz, r, r', r", ry
| respectively).
|
| When patients have to be given regular blood transfusions,
| especially on a long-term basis, the blood they receive has to
| be more precisely matched. That's often why there's always a
| huge push for black donors - because many black people suffer
| from sickle cell anaemia, for which the treatment is regular
| blood transfusions, they need blood that better matches their
| own.
| junon wrote:
| This is fascinating, thanks for sharing. Are there more
| groups than just A, B and O?
| bearmode wrote:
| The ABO group system relates to a gene called ABO, which
| gives you your A, B, AB, or O type. I'm not aware of any
| other blood types in that system (though I'm just an eager
| blood donor, not a haematologist).
|
| There are lots of other systems though that add up to make
| your blood what it is. There's the Rhesus (Rh) system I
| mentioned before, but the main ones also include the MNS
| system, the P system, the Lutheran system, the Kell system,
| the Lewis system, the Duffy system, and the Kidd system. As
| far as I know, Kell is the third most immunogenic system
| after ABO and Rhesus.
| roywiggins wrote:
| They apparently discover new sets of blood groups every few
| years, there are some vanishingly rare types.
|
| https://www.wired.com/story/new-blood-types/
| _tom_ wrote:
| Another comment says this is based on the donor. So, if you
| can self donate, or find one matching donor, you should be
| able to get a match every time.
|
| Obviously, custom tailored stuff is likely to take longer to
| develop, but it seems feasible.
| echelon wrote:
| It's so complicated.
|
| Just one more example: infants express a different set of
| hemes that have higher oxygen binding affinity. The switch
| from fetal to adult heme is being investigated as a potential
| cause of SIDS.
| Noumenon72 wrote:
| How do you make the stem cells produce the certain rare blood
| type that you need? What distinguishes it?
| nigerianbrince wrote:
| The blood group of the person who donated stem cells.
| _tom_ wrote:
| If we can grow it with whatever factor James Harrison had, that
| would be another huge benefit.
|
| https://www.cnn.com/2018/05/11/health/james-harrison-blood-d...
| eloff wrote:
| Wow, what a legacy that man left behind. I don't trust the
| numbers in the article, but even if his impact was a fraction
| of the 2.4M lives saved, he's had a remarkable impact in
| Australia. Thanks for sharing!
| steve_mcdougall wrote:
| It's well and truly Morbin' time
| solatic wrote:
| Obviously if this succeeds, then the life-saving implications are
| tremendous. It would become practical to keep a stock of lab-
| grown blood in ambulances, as it can just be rotated out when it
| expires, but the immediate availability of blood in the field can
| mean the difference between life and death.
|
| I just hope that blood donation doesn't go away as a result.
| There are both ethical and personal benefits - ethical, because
| it's a visceral experience of doing something good for society
| that most people can do, and with little effort; personal,
| because of potential health benefits from donating blood, see
| e.g.
| https://jamanetwork.com/journals/jamanetworkopen/fullarticle... .
| clintonb wrote:
| This is not a solution to a general need for blood, but a need
| for rare blood types. Hospitals may keep the lab-grown rate
| blood, but not ambulances.
| russdill wrote:
| I think a lot of people commenting just didn't read the
| article. The feedstock is donor blood.
| tempestn wrote:
| Initially, but once the technology is proven I don't see why
| it wouldn't become more generalized over time.
| Terr_ wrote:
| I imagine that donations will continue to be important for a
| range of subtler purposes, such as using the plasma for
| immunological stuff.
| gus_massa wrote:
| Donation to get antigens for the RH group to give to RH-
| mother after a RH+ baby is an important application. For
| example https://edition.cnn.com/2018/05/11/health/james-
| harrison-blo...
| tait wrote:
| Right idea, but I think maybe you may have used the wrong
| word.
|
| The donation is to get antibodies.
|
| Antigens are are the stimulus that causes the body to form
| antibodies.
|
| We give the Rh- mom antibodies so they bind to antigens on
| the blood from baby; the idea being that "hiding" the
| antigens from mom's immune system will prevent her from
| making her own antibodies.
| armchairhacker wrote:
| also financial: some people rely on blood donations for extra
| cash to pay for food and bills. Though, there are better ways
| to give people opportunities...
| bearmode wrote:
| You don't get paid to donate blood, you get paid for selling
| your plasma to pharmaceutical companies.
| AkshatJ27 wrote:
| People get paid to donate blood?
| doliveira wrote:
| Yeah, sounds to me like one of those cases where it's best
| to have a social reward rather than a financial one.
| Inversechi wrote:
| Germany does.
| hnbad wrote:
| _Germany_ doesn 't. There are some for-profit options for
| donating blood _in_ Germany but the most widely know way
| to give blood is with the German Red Cross, which does
| not pay donors unless you consider a small meal or the
| occasional swag (e.g. squishy balls) "payment".
|
| As I understand it, some hospitals offer payment for
| blood donations but if you want to get paid the most
| reliable options are probably pharmaceutical companies.
| By number of donors, both are probably eclipsed by the
| Red Cross though, which by its nature heavily relies on
| volunteer work.
| cyxxon wrote:
| As a German, I now several people here who donate blood
| and get paid money for it (e.g. here
| https://www.blutspendedienst-owl.de/blutspende.html), but
| more people do indeed donate plasma since they get more
| money per session and can donate more often (e.g. here:
| https://www.cslplasma.de/faqs but I don't see their
| monetary rewards on the page anywhere).
| Dunedan wrote:
| Somebody on Reddit recently did collect what one gets for
| donating blood in different areas of Germany: https://www
| .reddit.com/r/de/comments/xoqyay/aufwandsentsch%C...
|
| What you can see from that is that a
| "Aufwandsentschadigung" of ~20EUR is pretty common.
| mschuster91 wrote:
| What, where? Most of blood donations are made through the
| Red Cross, they don't give people anything.
| wongarsu wrote:
| If you wait for the next blood donation to be advertised
| for you, it will be from the Red Cross or similar and you
| get a free sandwich or something to that effect. If you
| actively search for options to donate, chances are it
| will be at the local hospital that will pay you around
| 20EUR for it and offer much more frequent options.
| otachack wrote:
| I believe you can get paid for donating your plasma
| components.
| KyleSanderson wrote:
| In the US, yes.
| guynamedloren wrote:
| Not paid to donate blood, as far as I know, but plasma. I
| did this a handful of times in college for extra cash.
| doliveira wrote:
| They still pierce you to remove blood and you get paid
| for it, don't you? I don't think "it's just the plasma"
| makes much of a difference.
| asib wrote:
| It does with respect to how frequently you're able to
| donate. In the UK, blood donation can be no more frequent
| than once every 12 weeks (for men). Plasma can be donated
| up to once every 2 weeks.
| PeterisP wrote:
| They pierce you to remove blood _and put it back_. You
| get to keep all the non-plasma components - blood cells,
| etc.
| doliveira wrote:
| So...? The ethical (political? social? moral?) component
| seems the same to me.
| senkora wrote:
| I don't think this is the right way to think about it. If
| donating blood is no longer a useful societal good, then there
| are no ethical benefits. If there are health benefits to
| bloodletting, then we can do that independently of donating the
| blood.
| TheSpiceIsLife wrote:
| And are those substances filtered out before being used?
| Could a recipient end up with higher concentrations in their
| blood?
| wongarsu wrote:
| Blood transfusion comes with a bunch of health risks. When
| it is done you generally have bigger problems than some
| PFAS accumulation.
| lesuorac wrote:
| While your article calls out PFAS in firefighters, there are
| people who for other reasons need blood letting. It's one of my
| biggest gripes with blood donation in the US is that those
| people are prohibited from donating blood because they're
| getting "value" from doing so (instead of having to pay
| somebody to draw their blood the red cross would be drawing it
| for free -- note, the blood isn't unusable for any other reason
| than drawing it provides value to the donater).
|
| Like you have a population that must give blood by some means
| and regularly the various blood banks complain about a shortage
| and they never seem to be able to put two and two together ...
| kyleyeats wrote:
| This actually reversed just this year, with most major blood
| banks (following the example of the Red Cross) now allowing
| donations from diagnosed hemochromatosis patients.
| tait wrote:
| I would love to see more donor centers allow hemochromatosis
| patients to donate.
|
| I think there is not actually regulatory ban. Last I looked
| into this, it was because of the conflict of interest - the
| FDA requires blood from donors with hemochromatosis be
| labeled as such.
|
| And even that requirement can be worked around. See, for
| example, https://clinicalcenter.nih.gov/blooddonor/donationty
| pes/hemo.... Background, most centers charge for therapeutic
| phlebotomy but obviously not for volunteer blood donation.
| The exception is permissable if the center agrees to allow
| the patient's blood to be drawn for free, whether or not they
| would qualify as a blood donor.
|
| The issue with "getting value" from donating is that people
| sometimes lie in order to be able to get that value. The
| downstream issues can be very painful - I have personally
| taken care of patients who got HIV or hepatitis from blood
| transfusion. I am pretty sure any of them would emphatically
| agree it is important to ensure the blood supply is as safe
| as possible.
|
| So it can be done, but it has to be done carefully.
| dsign wrote:
| Well I do hope that this succeeds beyond the wildest
| expectations, and blood-donations go the way of the horse[^1].
| We can cultivate ethics in everything else.
|
| --------------------------------
|
| [^1]: We still have horses. So there is a chance some people
| will become recreational vampire-feeders and some people will
| adopt vampirism as a hobby. Fine, I won't judge.
| hutzlibu wrote:
| "So there is a chance some people will become recreational
| vampire-feeders and some people will adopt vampirism as a
| hobby. Fine, I won't judge. "
|
| Not very surprising, that is already a thing.
|
| Edit: https://en.m.wikipedia.org/wiki/Clinical_vampirism
| frozenport wrote:
| >>then the life-saving implications are tremendous
|
| Are people in medical settings dying because of a lack of
| blood? It seems that unless you're in some exotic blood group
| you will likely find a compatible donor, and it is not clear as
| to severity of an imperfect match to rarer groups like the
| mentioned "Bombay" group.
| ip26 wrote:
| Your parent is theorizing that people in edge medical
| settings are. For example, an EMT might not be able to give
| you a transfusion while you lay bleeding in the dirt, because
| they may not have twenty units of blood to spare in the bus.
| kadomony wrote:
| Isn't this the plot to the movie Daybreakers? True Blood? Morbin'
| time?
| thecosas wrote:
| Was thinking this too; vampires will soon be free to come "out
| of the coffin" :-)
| godmode2019 wrote:
| yjftsjthsd-h wrote:
| Apparently it's still derived from blood, just they can grow
| more to "stretch" it, so vampires can survive with _less_ blood
| from the peasants. :)
| dang wrote:
| Please don't do this here.
| [deleted]
| boxed wrote:
| > The bulk of blood transfusions will always rely on people
| regularly rolling up their sleeve to donate.
|
| I always cringe when I read sentences like that. "Always"?
| Really? How could you possibly know that?
| [deleted]
| harry8 wrote:
| ...seems likely to always rely on...
|
| Poor expression. (May be completely wrong too for all I know,
| but I think it's the expression that is rubbing you up the
| wrong way).
| cultofmetatron wrote:
| and 4kb of ram is all you'll ever need!
| pcurve wrote:
| "some groups were "really, really rare" and there "might only be
| 10 people in the country" able to donate."
|
| oooof.... I knew some blood type was rare, but this is another
| level.
| d4mi3n wrote:
| What's more is that the identities of those people need to be
| protected lest they be bombarded constantly for lab studies or
| requests for life saving donations.
|
| Many counties have laws about paying for blood donations and
| don't allow donors to be compensated in any way, so they either
| need to take on the financial burden of flying to wherever
| their blood is needed or refusing to take on the financial
| burden and knowingly allowing someone to die.
|
| It's not fair to them and while most of these laws prevent
| darker forms of abuse of vulnerable demographics, they don't
| really account for cases like donation of rare blood types.
| tait wrote:
| > so they either need to take on the financial burden of
| flying to wherever their blood is needed or refusing to take
| on the financial burden and knowingly allowing someone to
| die.
|
| Is that a real case or hypothetical? If real, I would like to
| explore further as it does seem rather inappropriate.
|
| In my experience, the blood can be drawn locally and then
| sent to the recipient. That's also true for bone marrow &
| peripheral blood stem cell donations.
|
| Source: I am a transfusion medicine physician.
| beambot wrote:
| Always reminds me of this:
|
| > Harrison, known as the "Man With the Golden Arm," has donated
| blood nearly every week for 60 years. After all those
| donations, the 81-year-old Australian man "retired" Friday. The
| occasion marked the end of a monumental chapter. According to
| the Australian Red Cross Blood Service, he has helped saved the
| lives of more than 2.4 million Australian babies.
|
| https://www.cnn.com/2018/05/11/health/james-harrison-blood-d...
| gus_massa wrote:
| It's a different case. The article you posted is about
| someone that has a high level of RH antibodies.
|
| In the main article, the rare blood type is because the the
| A, B, AB, 0 and RH+/RH- groups are due to 3 antigens (2^3=8).
| But there are like 20 or 25 more antigens that your blood may
| or may not have, so there are like 2^23 or 2^28 blood types.
| Some are very rare, some combinations are very rare. Most of
| the time the other 20 antigens don't produce a reaction that
| is so strong [1], so for most transfusions it's enough to
| classify using the A, B, and RH.
|
| [1] Why? I'd really like to know why, or if I'm
| oversimplifying too much.
| tait wrote:
| Ask and ye shall receive!
|
| To answer [1] Why?: 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://professionaleduca
| tion.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.
|
| Each of those blood groups will have two or more versions.
| For example, there is the Kell blood group, which has two
| primary versions: you can express big K, little k, or both
| as Kell is a codominant system. Most people are homozygous
| little k (kk). When you are homozygous little k, you can
| make antibodies to big K (which is expressed on people who
| are Kk or KK). So, if you are homozygous little k, you are
| at risk of making antibodies on exposure to big K. Of
| course, not everyone is either big K or little k, that
| would be too simple. There are, I think, more than 20
| variants of K out there...
|
| More or less, each of those blood groups can cause antibody
| formation if you lack an antigen on the surface of those
| antibodies. In practice, the likelihood of an antigen
| causing antibody formation varies by antigen (the term
| there is "antigenic"). Also, the immunologic status of the
| recipient matters - obviously, someone who is
| immunosuppressed from an organ transplant may be less
| likely to form antibodies (that's the point of of the
| immunosuppression). Conversely, some people are more likely
| than most to form antibodies.
|
| Also, it appears that the immune system is more likely to
| form antibodies in other blood groups if a person already
| has antibodies. In practice, there is a recommendation from
| NHLBI to match for C, E, and K in patients who are going to
| be transfused often to try to avoid forming new antibodies.
|
| People 'naturally' form antibodies to A and to B antigens
| that they lack (I am group O and have both anti-A and
| anti-B antibodies). This is because they are exposed to
| those antigens in everyday life (the A and B antigen is
| found on some gut bacteria). And Rh-D is very immunogenic
| and clinically significant.
|
| When we test blood prior to transfusion, we attempt to
| identify what antibodies the patient may have. If they have
| no unexpected antibodies, just honoring blood and Rh-D type
| is usually enough. If they have unexpected antibodies, we
| go through a complicated process to identify blood that
| lacks those antibodies to try to avoid a transfusion
| reaction.
|
| (Now to modify that testing point, we know some antibodies
| are not clinically significant - that is, they do not cause
| significant transfusion reactions. So, we can, if we have
| to, give blood that is incompatible for clinically
| insignificant antibodies. We still try to provide blood
| negative for those antigens because we wouldn't find out
| this patient is the first to have a clinically significant
| version of the antibody. Also, the blood tests as
| incompatible with clinically insignificant antibodies, and
| we would prefer to give blood that tests as compatible).
|
| Sorry this is rambling a bit - I have to take my daughter
| to school. Happy to expand/clarify/etc. when I can get back
| to it.
|
| Source: I am a practicing physician board certified in
| "Blood Banking/Transfusion Medicine". My statements in this
| are still likely inaccurate, but hopefully in a useful way.
| I am not your lawyer, and I am not your physician.
| gus_massa wrote:
| > _Sorry this is rambling a bit_
|
| Nice write up! I'm happy with the answer, but I'd not
| mind if you decide to expand it. Anyway, I think it would
| be more useful if you reply to other questions in this
| thread, but you already have been doing that. I'll upvote
| your comment, but this is one of the ocasiones when I'd
| like a x2 upvote.
|
| Edit: If you don't mind a question: What do you [1] do
| with the people with big K that want to be blood donors?
| Ask them not to donate[2]? Do you tell them? Label the
| blood as big K and be more careful?
|
| [1] "You" as the impersonal "you". I could have written
| "the system" or something more accurate.
|
| [2] I guess they can donate. Otherwise they will be
| extremely unhappy.
| tait wrote:
| Thanks! Your comments are encouraging.
|
| [1,2]: Most people don't have antibodies, so big K+ blood
| is fine for most people (we worry about avoiding
| transfusing big-K positive blood into big-K negative
| people who will be transfused many times, such as
| somebody with sickle cell disease, it's not really a
| major issue for most people getting a rare transfusion).
|
| So, K+ people are definitely allowed to donate. Also,
| there are people who have antibodies to little-k, and so
| they would actually need big-K homozygous blood.
|
| When we need blood that is big-K negative, such as for a
| chronically transfused patient or one with antibodies to
| big-K, we try find units from people whose units were
| previously identified to be big-K negative. If they don't
| have any, the donor center can screen blood for them. We
| then verify compatibility with a crossmatch (reacting
| plasma from the patient with RBCs from the unit to make
| sure there is no reaction).
|
| Remember there are lots of other blood types - big-K is
| one we have to match sometimes. Little-k is another.
| There are at least 70 altogether, so we can't really even
| try to match all of them. Even matching C, E, and K is
| straining the ability of the system to provide special
| antigen-negative blood.
|
| It will be interesting to see what the long-term
| applications of lab-grown blood will be. I do worry about
| rare blood not being as available.
| pcurve wrote:
| I wonder if they were able to find additional sources to
| replace him...
| [deleted]
| nigerianbrince wrote:
| Don't people with such blood groups preserve their own blood
| for emergencies?
| tait wrote:
| Some can and do, but there are some challenges for it being a
| general solution:
|
| - Some people don't know they need rare blood (because they
| didn't have the antibody at first, then found they had it
| later).
|
| - Some people may donate blood to have it available for a
| need, then a need comes up (either themselves or someone
| else). At that point, the blood gets used up - what happens
| when the need is greater than the number of stored units?
|
| - Some people may not be able to donate. We had a patient
| with something north of 9 antibodies who, due to sickle cell
| disease wasn't able to donate - (banking blood for long term
| storage requires freezing, which doesn't work with blood from
| patients with sickle cell disease).
| photochemsyn wrote:
| For more comprehensive report, see:
|
| https://www.bristol.ac.uk/news/2022/november/labblood-study....
|
| > "The lab-grown blood cells are all fresh, so the trial team
| expect them to perform better than a similar transfusion of
| standard donated red cells, which contains cells of varying ages.
| Additionally, if manufactured cells last longer in the body,
| patients who regularly need blood may not need transfusions as
| often. That would reduce iron overload from frequent blood
| transfusions, which can lead to serious complications."
|
| They discuss automating the process, but the costs are still
| likely to be high as you'd need near-clean-room standards of
| sterility to avoid contamination problems - although that's also
| a problem with blood donation. Notably, some countries (incl USA,
| China) allow people to sell their blood, which tends to draw in
| poor and desperate people who may be more at risk of having
| transmissible diseases:
|
| https://www.theatlantic.com/business/archive/2018/03/plasma-...
|
| In the long run however, this might become the normal process.
| Bio-synthetic blood cell production has been talked about for
| over 20 years, it's cool to see it actually happening. (Synthetic
| immune system cells are also an interesting possibility, i.e.
| white blood cells).
| zdragnar wrote:
| Something of a minor nit, but the US does not allow blood
| donors to be paid, only plasma donors.
| tait wrote:
| That's right, and I have taught that point to trainees.
| However, there is a subtlety and I am sharing it as penance
| for having taught incorrectly:
|
| The FDA does allows blood donation by paid blood donors. The
| blood must be labeled as from paid donors, but it is legal.
|
| See https://www.statnews.com/2016/01/22/paid-plasma-not-
| blood/ for example...
| habitue wrote:
| > The bulk of blood transfusions will always rely on people
| regularly rolling up their sleeve to donate.
|
| Who is this line for? It's comically certain about this
| _tom_ wrote:
| People literally ALWAYS say this when a new disruptive
| technology comes up. I'm not sure why, maybe people like the
| idea of stability?
|
| "Digital will never replace film"
|
| "Landlines will always be the majority of calls"
|
| "Computers are cool, but will never replace typewriters"
| tomcam wrote:
| Pretty neat. They take a pint of blood, separate out the stem
| cells, "guide" aka convert them (not explained, but I think it
| can be done with gene therapy and complicated physical/chemical
| treatment) to become red blood cells, and culture those red cells
| in vats.
|
| World-changing if it works.
| inglor_cz wrote:
| The price tag is important. So far, these therapies are
| expensive. If, in the future, the stem cells can be nudged into
| their work more cheaply, the effect will be world-changing
| indeed.
| 2Gkashmiri wrote:
| imagine falling into one of those vats, https://ibb.co/zhH2QYX
| this feeling is more like it
| tomcam wrote:
| We dodged a bullet! They're pretty small vats right now.
| Whew.
| 2Gkashmiri wrote:
| "vats" are supposed to mean big vessels. tumblers, glasses,
| dishes and trays "mean small", just small nitpickings
| tomcam wrote:
| A vat could be 30 gallons and still not be enough to fall
| into
| dotancohen wrote:
| Love isn't even a few grams, but you could still fall in
| love.
| nottorp wrote:
| I wonder if it's white...
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