The history of discovering a blood group

Introduction

Without a doubt, the evolution of human blood groups has a past as old as man himself. There are at least three theories concerning human blood groups evolving and mutating. The global pattern of blood groups’ distribution depends on different environmental factors, such as disease, temperature, altitude, humidity, etc.

Everyone has learned about blood groups A, B, AB, and O. Doctors have to make sure that the blood type of a donor is compatible with the recipient’s blood when you get a blood transfusion, or the recipient can die. The blood group of ABO, as the blood groups are known collectively, is ancient.

Research published online in Proceedings of the National Academy of Sciences claims that humans and all other primates share this trait, inheriting these blood types from a common ancestor at least 20 million years ago and maybe even earlier. But it is also a scientific mystery why humans and apes have these blood types.

Background

Early Findings

In 1616, the English physician William Harvey reported his findings on blood circulation and published in 1628 his famous monograph, Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus (The Anatomical Exercises on the Motion of the Heart and Blood in Animals). His discovery that, in a closed system, blood circulates the body was an essential prerequisite for the notion of blood transfusion from one animal to another of the same or different species. In England, Richard Lower, a physician, pioneered blood transfusion experiments in dogs in 1665. Lower had transfused the blood of a lamb into a man in November 1667. Meanwhile, Jean-Baptiste Denis, court doctor to King Louis XIV, had also transfused the blood of lambs into human subjects in France and described what is probably the first recorded account of the signs and symptoms of a reaction to a hemolytic transfusion. Denis was arrested after a fatality. It was prohibited to transfuse other species’ blood into humans by an act of the Chamber of Deputies in 1668 unless approved by the Faculty of Medicine of Paris. Ten years later, the British Parliament also forbade transfusions in 1678. In the next 150 years, there was little progress

19th Century

In the 19th Century, interest was reawakened in England by the activities of obstetrician James Blundell, whose humanitarian instincts were aroused by the frequently fatal outcome of post-partum haemorrhage. He maintained that in such situations, it was easier to use human blood for transfusion.

German physiologist Leonard Landois demonstrated in 1875 that if the red blood cells of an animal belonging to one species are combined with serum taken from an animal of another species, the red cells usually clump and often burst, i.e. hemolyze.

He attributed the presence of black urine to the hemolysis of incompatible red cells after transfusion of heterologous blood (blood from another species). Thus, the risks of transfusing human blood from another species had been scientifically identified.

Discovery of ABO Blood Group.

It was not until 1900 when, at the University of Vienna, Karl Landsteiner discovered that others could be fatal while some blood transfusions were successful. By combining each of his staff’s red cells and serum, Landsteiner discovered the ABO blood group system. He has shown that some people’s serum agglutinates the red cells of others.

Landsteiner discovered that blood compounds, antigens, and antibodies induce the clumping of red cells when red cells of one type are added to those of the second type. Based on their responses to one another, he recognised three groups-A, B, and O. A fourth group, AB, was identified by another research team a year later.

Red cells of the A-group clump with donor blood of the B-group; those of the B-group clump with the blood of the A-group; those of the A-group clump with those of the A-group or B-group. This is because A-group cells contain both A-group and B-group antigens. Those of the O-group usually do not clump with either group because neither A-group nor B-group antigens are present. In the practice of blood transfusion, the application of knowledge of the ABO method is of enormous importance because errors can have fatal consequences.

Landsteiner and Alexander Wiener discovered the Rh mechanism in 1940 when they studied human red cells with antisera produced in rabbits and guinea pigs by immunising the animals with the red cells of the Macaca mulatta rhesus monkey.

Later on, other blood types, such as Kell, Diego, Lutheran, Duffy, and Kidd, were identified. After antibodies were detected in patients, the remaining blood group systems were first described. Such results have also resulted from the search for an unusual unfavourable reaction in a patient during a blood transfusion that was previously consistent with it. In these cases, the recipient’s antibodies were produced in the donor’s blood against yet unidentified antigens.

For example, in the Rh system case, the presence of antibodies in the maternal serum directed against antigens present in the red cells of the child may have profound implications due to antigen-antibody reactions that trigger foetal erythroblastosis or newborn hemolytic disease.

Scientists are still unaware of these blood antigens’ function, even though it’s been more than a hundred years after Landsteiner’s Nobel Prize-winning work. Obviously, without them, type O, the most common type of blood, does just well. However, what scientists have found in the last Century are interesting associations between blood and illness types.

Bacteria may closely resemble specific blood antigens in some infectious diseases, making it difficult for antibodies to detect foreign invaders’ difference and the body’s blood. For example, type A appears more susceptible to smallpox, while type B seems to be more affected by some infections of E. coli.

New Findings/ Current world scenario

Scientists have also found that the ABO blood group has been only one of more than 20 human blood groups in the past hundred years. Another well-known blood group is the Rh factor, referring to the’ positive’ or’ negative’ in blood types, such as A-positive or B-negative. (Rh refers to the Rhesus macaques that were used in early blood group studies.)

Rh-positive individuals have Rh antigens on their red blood cells; Rh-negative individuals do not contain antibodies that target Rh antigens. In the often fatal blood disease erythroblastosis fetalis, the Rh blood group plays a role that can evolve in newborns if an Rh-negative female gives birth to an Rh-positive child, and her antibodies attack her child.

Many individuals, such as MN, Diego, Kidd and Kell, have never heard of the various other blood types, possibly because they cause smaller or less regular immune reactions. And in some cases, human beings do not develop antibodies against the antigens, like the MN blood group. The Duffy blood group is one “minor” blood type that does have medical significance. When the blood group invades the body’s red blood cells, Plasmodium vivax, one of the parasites that cause malaria, latches onto the Duffy antigen. Thus, individuals who lack the Duffy antigens appear to be immune to this type of malaria.

Conclusion

While researchers have discovered these fascinating connections between blood groups and disease, they still do not understand, first and foremost, how and why specific blood antigens have evolved. These blood molecules are a reminder that human biology still has a lot to think about.