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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."
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!
No! It's a *SIG*. Keep the Special Interest Groups away! (Con joke!)
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...
Javascript + Nintendo DSi = DSiCade
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. 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.
But this is slashdot. A slashdoter who didn't build his own computer is like a Jedi who didn't build his own lightsaber!
http://biomed.brown.edu/Courses/BI108/BI108_2005_G roups/10/webpages/HBOClink.htm
"Oh drat these computers, they're so naughty and so complex. I could pinch them."
Marvin the Martian
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.
Not a member of the General Public
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.
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.
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.
I don't read AC A human right
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 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.
...
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.
-- The Genesis project? What's that?
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!