Question

who is credited with discovering the ABO, Rh blood group antigens and what was the significance?

Answer 1

1) ABO blood group system was discovered by Karl Landsteiner in 1990. He discovered the three different alleles in the inheritance of blood group in man. These alleles were designated as I^A, I^B, and I^O. These alleles determine the presence of certain antigens called Agglutinogens in the RBCs. ABO blood group system is generally known as multiple allelic system.

Individuals belonging to A group carry the antigen A (agglutinogen A) in their RBCs.

B group individuals carry B antigens (agglutinogen B) and

AB group individuals possess both A and B agglutinogens

O group individuals carry no antigens at all.

These individuals may also possess certain natural antibodies called agglutinins in their blood plasma. Thus A group persons carry the agglutinin , B group individuals carry agglutinin , O group persons have both and agglutinins and the AB group individuals possess none.

Significance: Besides its medical importance, the discovery of ABO blood group and other blood group has been of forensic importance. Since the ABO system shows Mendelian inheritance, blood group provide evidence in paternity suits.

Rh blood group: In addition to A and B antigens, RBCs contain another factor known as Rh antigen. It was discovered by Landsteiner and Weiner in 1940 in the RBCs of the Rhesus monkey, and hence the name Rhesus factor or Rh factor. Since this factor has also been reported in human beings. Those individuals who possess the Rh factor in their RBCs are called RH positive (Rh⁺) and those without Rh factor are called Rh negative (Rh^-).

The Rh antigen has no natural antibody. However, the production of Rh antibody can be induced by sensitizing the Rh^- individuals with Rh⁺ blood. Even a small amount of Rh⁺ blood can evoke the production of Rh antibody in the Rh^- person. The problem of Rh incompatibility is that the immature red blood cells or the erythroblasts appear in the circulating blood. This has given the disease called Erythroblastosis foetalis.