All Blood Converted to Type O?

UnanimousCoward writes "The BBC is reporting that scientists claim to have discovered a technique to convert all blood into Type O with the discovery of an enzyme that can strip the A and B antigens. This has implications to transform the stored blood supply into transfusable blood for all. It does not address the RH negative issue, however."

O negative, eh?

[arthurh3535]

While I won't mind the ability of people to donate to me, the benefit is actually pretty amazing. O Negative is the preferred donor type, as (IIRC) anyone can accept it, but no other blood type works for us poor O Neg's.

So this technology could literally save my life!

Re:individuality

[UnknowingFool]

I take it that you didn't RTFA. The article says nothing about converting the blood in your body to O. The article was all about converted donated, stored blood to type O, the universal donor blood. This breakthrough (if found to be safe and effective) means that type specific donations could be converted and thus increases the supply of available blood. In a shortage now, some patients don't get the blood they need because the only available types are not compatible. This will help mitigate that problem. Of course there will always be a need for type-specific blood but for emergency transfusions, this could save lives.

Re:That's great until...

[AKAImBatman]

Until we find that new disease that only destroys type O blood.

I wouldn't worry about it. This is only for Type-O transfusions. Since a transfusion doesn't change your blood type (it just supplements your existing plasma until your body can manufacture sufficient replacement quantities), you won't have to worry about those "new diseases". Unless you're normally O-negative, that is...

Blood made suitable for all

[sas-dot]

Here more info from Nature [nature.com]

Scientists have discovered enzymes that can efficiently convert blood groups A, B and AB into the 'universal' O group -- which can be given to anyone but is always in short supply.

The two novel glycosidase enzymes were identified in bacteria by an international team led by Henrik Clausen of the University of Copenhagen in Denmark. The researchers hope that the enzymes will both improve the erratic supplies of blood around the world, and also the safety of transfusions. Clinical trials to test the safety and effectiveness of their converted blood are being planned.

The ABO blood-type system is based on the presence or absence of the sugar-based antigens 'A' and 'B' on red blood cells. Type O blood cells have neither A nor B antigens, so may be safely transfused into anyone. But types A, B and AB blood do, and cause life-threatening immune reactions if they are given to patients with a different blood group. The bacterial glycosidase enzymes strip these antigens away from A, B and AB blood.

The idea of such antigen-stripping goes back to the early 1980s, with the discovery of an enzyme in coffee beans that removes B antigens from red blood cells1. Early-stage clinical trials showed that the converted blood could be safely transfused into individuals of different blood groups; no traces of enzyme or antigen remained to cause reactions2. But the enzyme reaction was far too inefficient to make large-scale conversion practical.

Clausen's team screened 2,500 extracts from different bacteria and fungi for their ability to cleave off A and B antigens. The newly discovered bacterial 'B' enzyme is nearly 1,000 times more efficient then the coffee-bean B enzyme -- the additional discovery of an enzyme to remove A antigens means that all blood types can now be converted. The work is reported in Nature Biotechnology3.
(snip)

Duh

[Scott Lockwood]

It does not address the RH negative issue, however.

Duh. Rh factor is a combination of several different genes. Blood type isn't controlled by those.

Also, it should be noted that, unlike what several of the replies thus far seem to think, this won't change your blood type - it will only alter blood that has already been removed from the body for future transfusion. Your body will still produce blood of whatever type you normally produce. Also, it basically has the added implication of making more than just O neg the universal donor. After all, if I can 'strip' A, and B off of cells, then A neg, B neg, and AB neg also become universal donors.

Re:Synthetic Blood

[WhyDoYouWantToKnow]

There have been attempts to synthesize RBC's (red blood cells). The linked article discuses a current synthetic blood product. While there are many advantages, there are still a number of issues to overcome before this becomes a viable alternative to RBC transfusions.

http://biomed.brown.edu/Courses/BI108/BI108_2005_G roups/10/webpages/HBOClink.htm [brown.edu]

Re:Synthetic Blood

[jimstapleton]

Actually, only red blood cells lack a nucleus, the rest of the blood cells have them. Also there are three locations of blood cell development - marrow, liver, and I think spleen or pancreas (may be wrong on both counts in the last one). But I don't remember which cells have which parts of the development where. It's been a while since I've studied that.

More than ABO and RhD blood groups

[kenrick]

Although ABO and RhD grouping systems are the most well-known and the most important, there are a myriad of other blood groups (about 29 last time I checked) that are of relevance when it comes to crossmatching blood for a patient.

Whilst this potentially is a great step forward, as always with biomedical headlines, it's not the be-all and end-all.

Fuzzy Types

[Doc Ruby]

There are more blood factors than just the ABO and Rh factors that contribute to defining exclusive immunological blood types [wikipedia.org], so this extremely valuable process is not a panacea [wikipedia.org].

Re:Synthetic Blood

[milamber3]

First off, it's the red blood cells that are important in the majority of transfusions so that is why the lack of a nucleus is pointed out by the gp post. Secondly, blood cells are created in the marrow so I'm not sure what your point is about development. Some blood cells do mature in other places (e.g. thymus and spleen) but you're not going to be getting any blood if you try to grow new cells out of a tissue besides the marrow.

Re:Awesome

[Anonymous Coward]

You don't "make a quick buck" by giving blood to the Red Cross.

That's why it's called a blood donation.

Re:Synthetic Blood

[norton_I]

Clinical trials recently finished for Polyheme by Northfield Labs, which takes expired blood and polymerizes the hemoglobin to make a long lasting, oxygen carying substitute for saline, which is currently used in amulences to maintain blood pressure but does not carry oxygen. It also showed the potential for a superiority to blood in massive trauma situations since it avoids the immune response.

Unfortunately, the initial reports from the trials failed to show even non-inferiority over saline, though there were multiple issues of coding errors by the 3rd party data analysis company, and they are in the process of reviewing the database to see if their conclusions were correct.

The work is very hard since you have to get FDA approval to do non-consent trials of an experimental procedure.

There are other procedures under development that use non-human blood as the hemoglobin source, but they are not to testing phases yet, and there are some additional problems that need to be solved to avoid rejection in those cases.

Re:O negative, eh?

[trianglman]

The time saved in testing injured patients alone to make sure that the right type of blood is given will save thousands of lives (I know it only takes a few seconds to do the test, but you've got to collect blood and take it to the lab and that takes a few minutes which some people may not have).

This is true, but, except in the most extreme of shortages, this isn't an issue. Most hospitals, in an emergency will simply transfuse a person with O+ blood (O- for women of child bearing age). While giving an O- patient O+ blood can have side effects, they are usually minor when it is only one pint, especially compared to imminent death. This most often only introduces new antigens that have to be dealt with on future transfusions and won't kill the patient. In general its important to avoid this, as there can be serious allergic reactions, but if its death or transfusion, a doctor will sign off on an emergency O transfusion. It can have serious repercussions on an unborn fetus, which is why women of a certain age are only given O- in these circumstances.

Credentials: Worked in a hospital blood bank for 3 years and another blood bank later for about the same.

Re:In the Meantime

[Beardo the Bearded]

Yes, the clinics have lists of medications and vaccinations that have a waiting period. It's a reasonably exhaustive list.

Don't worry about what's going to happen to the blood after you're done with it. After all, you're done with it. If it's suitable for use as blood, it will go to someone who might otherwise have bled to death. If it's not suitable in its current form, it may have the plasma removed and used, or it might go to some other technician to run some tests. (Like whether or not this enzyme can be used to strip the antigens out and convert the donation to Type O.)

Once, my wife had trouble giving blood and only gave a small (1/2) donation. They said - and this is the part you'll remember - "That's okay, dear. It's enough for a child."

Re:O negative, eh?

[senrable]

CMV is Cytomegalovirus [wikipedia.org] and is present in 50-85% of adults by the age of 40. In non immunocompromised adults, the virus is latent, but in infants or immunocompromised individuals (organ transplant recipients, chemotherapy patients, pregnant mothers, etc.) it presents a serious risk.

Please donate, you would be surprised at how many infants need blood transfusions (as well as many transplant recipients).

Re:Synthetic Blood

[Anonymous Coward]

http://en.wikipedia.org/wiki/Fluosol [wikipedia.org] You're welcome.

Re:Synthetic Blood

[tpjunkie]

That was a liquid chlorocarbon, which polymerized can be used to create teflon and other useful plastics. It has been well known for some time that these solutions can hold enough oxygen to be viable breathing solutions for applications like deep sea diving. However, that is in no way similar to a blood substitute. The problems with synthetic blood substitutes are myriad, including but not limited to the difficulties of creating a substance that can function as oxygen donor and CO2 recipient in the same manner as hemoglobin (which achieves this via an affinity curve that varies with pH) while tending to not be immediately filtered out by the kidneys or induce clotting.

Re:Synthetic Blood

[Firethorn]

As milamber3 said, it's the red blood cells they need, followed by platelets. If they could remove everything else, leaving a saline/glucose solution with rbc and platelets, they'd likely do it. Heck, there's situations where they'd want to remove the platelets as well.

In an emergency situation you wouldn't be worried about the nutritional substances. There it's about keeping oxygen flow up until they get to the hospital. Heck, with a working artificial blood substitute if that means they gotta run 5 gallons through you, they can do it.

The author of the article is confused about RH -

[GargamelSpaceman]

The author of the article doesn't seem to understand that 'X negative' is synonymous with 'Type X, RH negative' where X can be A, B, AB or O. See: http://en.wikipedia.org/wiki/Blood_type [wikipedia.org] The positive or negative in a blood type refers to the blood being either positive or negative for the Rhesus (RH) Factor. So there is no such thing as being AB-positive but negative for the RH factor. The preceeding is an oxymoron. Since the author of the article evidently does not understand this, the whole article is unclear and not to be trusted. Either the treated blood is ok for everyone ( both the A, B and also the RH antigens are removed by the enzyme ) or the enzymes remove A and B antigens but not RH antigens. In that case, the blood is not universally safe. Given the author's confusion, I would not hazard to guess which the actual case is.

Hey, let's all donate!

[PCM2]

I haven't heard anybody say it yet, so ... HEY SLASHDOT! Get out there and donate blood!

Donating blood is very easy and doesn't take a whole lot of your time. Typically you're not going to be light-headed or anything after you do it. It's recommended that you eat hearty before and after you donate, but how hard is that?

On the plus side, if you donate blood you are helping save somebody's life. LET ME REPEAT THAT. The blood you donate will be used to try to save somebody's life. There is absolutely no reason to give somebody a blood transfusion unless they've sustained a life-threatening injury. When's the last time you've had a blood transfusion? I've never had one, and I've messed myself up pretty bad. I hate to think about the kind of messed-up I'd need to be to require a pint of blood.

What's more, blood banks are regularly short of supply. Hospitals need blood. I know that in my area, they're always begging for extra Type O. I'm O positive. It's a pretty common blood type -- but that doesn't just mean that there's a lot of available supply. It means there's a lot of demand, too.

Consider this, too. Blood banks have all kinds of rules. Some of them you may agree with and some of them you may not. But the rules are in place. Among those rules: If you're a man who has ever had sex with another man since the 1980s, even just once, they don't want your blood. That's right -- gay dudes aren't supposed to donate. Same goes for people who have injected drugs -- even just once. Same goes if you've had a tattoo or piercing in the last 12 months. Same goes if you've spent more than a few months living in England in the last couple decades (it's the BSE thing). Same goes if you've, like, ever had sex with anybody who's a native of Africa. I'm serious, go offer to donate and look at the questionnaire ... the rules are harsh.

The point? Well, let's see. Gay dudes, people with tattoos, people who've gotten laid a lot, and people who have done serious drugs are not allowed to donate. I live in San Francisco. So, holy fuck, just who is donating blood in my town??! Not a joke ... I'm actually being serious. It seems to me that there's a pretty strong need for eligible and willing blood donors in my area.

So I donate. I believe you're allowed to do it every 8 weeks, in the U.S.

Re:Blood made suitable for all

[sokoban]

I doubt this is any sort of April Fools joke though.

Using a bacterial enzyme to cleave the terminal sugars from the A and B type antigen totally makes sense. You're just cleaving an alpha 1-3 bond between either N-acetylgalactosamine or galactose and galactose. Bacteria commonly have enzymes to digest alpha bonds, so it would only be a matter of trial and error to find the right enzyme.

Re:Damn.

[tdelaney]

That would be O- not O+. Negative RH can donate to positive RH, but not the other way around.

Re:Synthetic Blood

[chooks]

Actually graft vs. host is due to lymphocytes of the donor attacking the cells of the recipient and does not directly have to do with blood volume (although obviously, the more blood you get, the more foreign lymphocytes you will get). In most people this is not a big deal b/c the immune system of the recipient can handle the foreign lymphocytes appropriately. However in immunodeficient individuals (or young people with underdeveloped immune systems) this is not good, since they do not have the ability to protect themselves against the donor immune cells.

Re:Synthetic Blood

[Thwaites]

Just an FYI ...

You're correct about the marrow and liver creating RBC's. The other organ is the spleen (as you mentioned); however, the spleen only creates RBC's (haematopoeisis) up until around the 5th or 6th month of gestation. After that, the spleen behaves like an recycling plant, returning the components of RBCs undergoing apoptosis (controlled cell death) to the body.

The more you know!