Creevy groups

Blood groups are an individual biological feature of each person, which begins to form in the early period of intrauterine development and does not change throughout subsequent life. These groups are defined by an individual set of specific substances, known as group antigens or isoantigens, which are inherited.

Of greatest practical importance are isoantigens of erythrocytes, such as isoantigen A and isoantigen B, as well as antibodies against them that are normally present in the blood serum of some people, called isoantibodies - isoantibody a and isoantibody β. Depending on the presence or absence of isoantigens A and B, as well as isoantibodies α and β, in a person’s blood, their blood group can be divided into 4 types, designated by alphabetic and numerical symbols: 0αβ - blood group containing only isoantibody α, A(III ) – blood group containing isoantigen A and isoantibody β, B(III) – blood group containing isoantigen B and isoantibody α, AB(IV) – blood group containing both isoantigen A and isoantigen B.

It is important to note that only heterogeneous isoantigens and isoantibodies can be present in human blood, for example, A+β and B+α. If there are similar isoantigens and isoantibodies in the blood, such as A and a, red blood cells stick together into lumps, which leads to severe complications and even death. Therefore, when transfusing blood, it is taken into account that the transfused blood does not contain isoantibodies against the isoantigens of the blood of the person to whom the blood is administered. Ideally compatible blood for transfusion is blood of the same group.

The study of blood groups arose at the end of the 19th century and is an important branch of general immunology. Blood groups and blood transfusion are the basis of such an important treatment as blood transfusion, which has saved many millions of human lives.