Converting "A","B", and "AB" blood group to "O"

[Rania]

Hi all,

Can anyone provide with any information regarding this topic "Converting A, B, and AB blood group to "O"?

Thanks:)

[David Saikin]

I beleive this has been done successfully with "A" red cells but the others are works in progress. None are available for transfusion purposes yet.

[Doug@SJL]

I think what you are refering to is A, B, and A,B antigen removal from RBC's. I read a few months ago that in Europe (not sure of which country) they had accomplished this, but it was still not ready for actual testing. I forget exactly where I read the article, but if I remember or run across it, I will provide a link to it.

Doug

[MCrosby]

Dr. George Garratty is currently involved with a similar project. He gave a short lecture about it at the AABB conference in Anaheim last year. If you would like, I could send you a PDF file from it. PM your e-mail to me if you want to see it.

[Malcolm Needs ☆]

Rania, if I could have an email address, I've just completed an essay on this subject for my Continuing Professional Development file. Whilst I would not say that what I have written is by any means a brilliant piece of scientific work (actually, far from it), the references I cite may well be of use to you (but I really would suggest that you go back to the original references than rely on my own ramblings)!

[heathervaught]

I've heard it called "Enzymatic conversion"...an enzyme is used to cleave the sugars that specify ABO from the RBC, thus rendering it an "O". From what I understand, the RBCs are treated with an enzyme, then the enzyme is removed prior to transfusion by washing.

[Malcolm Needs ☆]

This is quite true, but the enzymes used are very different from the enzyme found in the green coffee bean used to convert group B red cells to group "O" red cells some years ago.

The enzymes used now work at a pH nearer to physiological pH and are more efficient. Whereas the enzymes used earlier were unlikely ever to be used at an "industrial level", the enzymes used by Martin Olsson and his group in Sweden seem capable of this upgrade and they have found an enzyme that will convert A2 red cells to group "O".

[kate murphy]

ZymeQuest in Beverly MA currently owns the US patent for enzymatic conversion of red cells to group O. Currently in clinical trials. No FDA licensed product as yet. Still a ways off.

[quint]

from web md

http://www.webmd.com/news/20070403/converting-blood-types-may-be-possible

Converting Blood Types May Be Possible

Technique Makes Type A, B, or AB Blood Act Like Type O Blood

By Miranda Hitti

WebMD Health News

Reviewed by Louise Chang, MD

April 3, 2007 -- Scientists have found a way to convert blood types in a test tube. If their approach works in people, it could be a boon to the blood supply.

The news appears in Nature Biotechnology.

The four blood types are A, B, AB, and O. They are based on the presence or absence of specific antigens -- foreign substances that cause the production of antibodies. Blood type is inherited.

To avoid potentially deadly reactions, type A blood can only be given to people with type A or type AB blood. Type B blood can only be given to people with type B or AB blood.

Type O blood is often in demand because it can be safely used in any patient.

Scientists have long looked for ways to make type A, type B, or type AB blood compatible with anyone. But until now, those attempts have had limited success.

Now, scientists report success with a new technique tested in a lab.

The researchers studied 2,500 enzymes made by fungi or bacteria and found two families of enzymes that make type A, type B, or type AB blood act like type O blood.

Scientists working on the study included Qiyong Liu of ZymeQuest, the Massachusetts-based company developing the enzyme technique.

Their technique needs further testing. But if it succeeds, it "would substantially reduce pressure on the blood supply," states a Nature Biotechnology editorial.

The editorialists included Geoff Daniels, PhD, FCRPath, of the Bristol Institute for Transfusion Sciences in Bristol, England.

[Malcolm Needs ☆]

There is a very thorough and excellent article/review about this in Nature Biotechnology.

Liu QP, Sulzenbacher G, Yuan H, Bennett EP, Pietz G, Saunders K, Spence J, Nudelman E, Levery SB, White T, Neveu JM, Lane WS, Bourne Y, Olsson ML, Henrissat B, Clausen H. Bacterial glycosidases for the production of universal re blood cells. Nature Biotechnology 2007, 25 (4): 454-464.

It is not for the faint hearted, however. I had to read it about 27 times before I understood the abstract!!!!!!!!!!!!!!!!!!!!!

[Malcolm Needs ☆]

I honestly can't remember if I've put this attachment on before.

If I have, I apologise.

If I haven't, it may, or may not, be of interest. You judge!

:)

Review of the current progress in developing universal red cell products and their potential to.doc