Specific sectors and field actions: the challenge of collecting rare blood

For the second year in a row, the French Blood Establishment (EFS) warns of the challenges of donating rare blood. In search of the precious red fluid, these blood groups are the most sought after. Each of them actually affects fewer than 4 in 1,000 people. “Anyone can be a carrier of rare bloodEFS explains. However, in metropolitan France, there are more people from the African continent, the West Indies and the Indian Ocean, or people of African descent. »

From November 14 to 20, this public institution, the only civilian operator of blood collection and transfusion in France, multiplied its actions in this field to increase the awareness of this population about the importance of donation. “During Awareness Week 2021, rare blood donations increased by 40% compared to the same week in 2020. »notes EFS, for whom it is still too early to assess this year’s campaign.

Rare blood, says EFS “Blood groups whose frequency in the population is low enough to create an imbalance between the number of donors and the needs of patients”. When a patient with rare blood needs a transfusion, the most compatible blood is sought, which minimizes the risk of rejection. But finding such blood is a challenge.

“370 different blood groups”

A person’s blood group is determined by the combination of molecules or fragments of molecules (“antigens”) that are present or absent on the surface of his red blood cells. For a risk-free transfusion, the donor’s red blood cell antigens must be as close as possible to the recipient’s. Otherwise, the latter’s immune system will reject the transfused blood.

The most famous blood types are A, B, O and Rhesus + or -. In Europe, for example, 45% of individuals are group A, 43% group O, 9% group B, and 3% group AB; 85% are Rhesus positive and 15% Rhesus negative. However, the diversity of human blood goes beyond these two classifications. It’s like our hair color. There are hundreds of shades besides blonde, brown and red. For example, strawberry blonde, ash, golden, platinum…

“There are about 370 different blood types, of which almost 200 are considered rare in France”, says Jacques Chiaron, anthropologist and director of EFS PACA-Corse. According to the National Reference Center for Blood Groups (CNRGS), about 700,000 people in France have a rare blood group. When a person is found to have a rare blood type, they are given a special card – which they are encouraged to carry with them at all times in case of emergency hospitalization.