Blood group system
Blood group system
Karl Landsteiner in 1901 revealed that blood of a person, if transfused to another person, will have differences and result eventually as a cause of shock or jaundice. He classified the human blood groups as A, O, B and AB as well as demonstrated that the transfusions of blood done between the people having the blood group A and people having the blood group B. the transfusions of A and B showed no signs of destruction of blood cells and this calamity took place when one person was transfused with a different blood group. The blood group AB is also another important group found in 1902. The blood group to be written in capital letters, while the recessive traits to be written in small letters or lower case letters is not followed. However, as per tradition the antigens of the red blood cells are written as alphabetical designations. A numerical system is being instituted for blood transfusion of the international society to assist in standardizing the red blood cells group terminology. Mandate is given to each system and is designated a letter and a number. Similarly, each antigen is sequentially numbered. By now nearly 20 blood group systems as well as 7 red blood antigens are defined. However, the naturally occurring antibodies are written as Ii, H and Lewis. The other systems are iso-antibodies resulting from the pregnancy and incompatible transfusions. The MNS system was followed by injecting human red cells to animals and the antigens that represent are M, N, S and S. the antigens S and s develop immune characteristics. P system is also followed in the same method and P1 is the common antigen having variable expression. Lutheran system has Lua and Lub antigens, where Lua is rare as it is negative phenotype. The Lutheran group genes are responsible for ABH substance secretion. Kell system has four antigens. The Kidd system comprises of two antigens system Jka and Jkb. Pregnancy or Incompatible transfusion leads to antibodies formation of blood groups, in case the receiver is short of the relevant antigen. The Rhesus system is utilized in the blood grouping systems. This is also a discovery of Landsteiner. This system stated that clumping of red cells together on the red cells by the antiserum is accepted as having Rh factor and is termed to be Rh positive and if a person’s cells lack the Rh factor, he is termed to be Rh negative. Fisher system states that if a person has one antigen namely C, D or E, they are considered to be Rh positive. People having cde genotype are considered as Rh negative. The donors in Rh types also having C or E are considered as Rh positive.