Blood group conversion method may end shortages

SCIENTISTS have developed a simple method of converting blood from one group to another.

The breakthrough could potentially mean the end of blood shortages by boosting much-needed supplies of group O-negative blood.

Blood that is O-negative is known as “universal” because it can be given to anyone.

Writing in the journal Nature Biotechnology, an international team of researchers described how they converted blood from group A, B or AB to group O. The process uses bacterial enzymes as biological “scissors” to cut sugar molecules from the surface of red blood cells.

Giving patients the wrong blood may result in a severe immune reaction and even death.

People in groups A and B have blood containing one of two sugar molecules which can trigger an immune response. Those in group O have neither of these “antigens” while those in group AB have both.

Patients produce antibodies against the antigens they lack. For this reason, AB individuals, who lack neither, can safely receive blood from any group. But group A patients cannot be given a transfusion of group B blood, and vice versa.

Group O patients react badly against A, B or AB blood. However, their own blood, having neither of the sugar antigens, is suitable for people from all the ABO groups. Group O donors are therefore always in demand, and O blood often in short supply.

The scientists, led by Professor Henrik Clausen, from the University of Copenhagen in Denmark, started by screening 2,500 types of fungi and bacteria, looking for useful proteins.

Two bacteria, Elizabethkingia meningosepticum and Bacterioides fragilis, yielded enzymes capable of removing both A and B antigens from red blood cells.

Trials will have to take place before group O blood produced by the conversion method can be used in hospitals.

Two experts from Britain and Canada, commenting on the new findings, said the approach looked pro-mising.