- Scientists have discovered two enzymes formed by gut bacteria that can convert type A blood into type O blood
- There are four blood types (A, B, AB and O), and only type O can be given to persons of any blood type during an emergency. Giving any other non-matching blood can be life-threatening
- However, this new discovery could revolutionize blood banking and help overcome the constant blood shortages faced by hospitals across the world
Scientists at the University of British Columbia have discovered a potential method to convert type A blood into universal type O blood, a finding that could greatly help in improving the availability of blood for patients needing a lifesaving transfusion. The findings of their research appear in Nature Biology.
Why O Type Blood Is Considered As Universal Donor?
- In blood banking, the person who donates blood is termed a donor and the person receiving the blood is termed recipient
- There are four blood types (A, B, AB and O); only type O can be given to persons of any blood type (since type O is universal donor blood) during an emergency if the exact required type is not available
- For instance, if a person with type A blood is mistakenly given blood transfusion with type B blood, the B type proteins in the transfused blood will induce a potentially life-threatening reaction by the immune system of the patient which recognizes the B antigenic protein as a foreign entity
- However, type O red blood cells have no A or B antigens on their surface; instead, they carry a neutral "H" antigen and don't induce any reaction in the recipient; therefore O type blood can be safely given to persons of all blood types
- On any given day, in medical centers across the US alone, there is a need for about 16,500 liters (35,000 pints) of donated blood for emergency surgeries, elective surgeries that have been prescheduled and routine transfusions for other medical conditions. Consequently, there is a constant shortage if the required blood type or sufficient supply of type O is not available in the hospital blood bank. The scenario is pretty much the same worldwide
- Thus in blood banking, O type blood is considered highly valuable
Converting Type A Blood to Type O Blood
- Type A blood is the second most common blood type after O blood. If type A blood can be converted to type O blood, this could revolutionize blood banking and prevent existing blood shortages across the world
- Until now efforts to convert type A blood to type O have met with limited success since the earlier enzymes were not able to completely remove the A antigen and the process was not economical
- The current research team led by Stephen Withers, a chemical biologist at the University of British Columbia (UBC) in Vancouver, Canada, decided to look for a better enzyme among the gut bacteria after trying unsuccessfully for four years
- Some of these gut bacteria latch onto the gut wall, and "eat" the mucin that lines the gut wall. The gut mucin is a glycoprotein chemically similar to the antigenic protein on the surface of the red blood cells
- During their research, the team isolated the bacteria Flavonifractor plautii from human stools, and found genes that encode two enzymes that could remove important parts of the surface A antigen from type A blood
- When these two enzymes were added to type A blood, they efficiently removed the A antigen from the red blood cells, essentially converting them to type O blood
- The O type blood thus obtained could be given to any patient without inducing an immune reaction
Future PlansThe future studies will aim to ensure the complete safety of the converted type O blood.
- The team to carry out more research to ensure that gut bacterial enzymes completely all the A antigen present in type A blood
- They also need to ensure that the bacterial enzymes do not change anything else on the red blood cells that could create problems later
- Type A blood converted to universal donor blood with help from bacterial enzymes - (https://www.sciencemag.org/news/2019/06/type-blood-converted-universal-donor-blood-help-bacterial-enzymes)