Slashdot Mirror
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."
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)
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