Rhesus System is a Complex Blood Group - Article Example

Rhesus system is a complex blood group Introduction Blood is a vital fluid of our body which has four main functions. It helps transport nutrients toall the cells of the body and also carries waste, produced by the cells to the organs to be removed. The second main function is that of regulating body temperature by evenly distributing heat from the warm parts of the body to the cooler parts. The third is that it prevents excess flow of the blood in injuries through the process of coagulation or clotting of the blood. The fourth and not the least important is that it helps body to fight against diseases through a complex process of immunization by producing requisite antibodies against the foreign agents called antigens. The blood can be broadly classified into 2 groups or types so that blood transfusion between two bodies can take place successfully. The two main blood groups are ABO system and Rhesus system of blood groups. In the First blood group case, a person can either be A, B, AB and O where A, B and AB are types of glycoprotein that are found in RBCs. O shows the absence of the said antigens in the blood group. The Glycoproteins are better known as antigens. AB type of blood group is known as universal receiver and can accept blood from everyone but can give blood to only those who have AB type of blood. O type of group is called universal donor who can give blood to everyone but receive blood only from person who has ‘O’ type of blood group. A and B types of blood can each receive blood from those who either have blood group ‘O’ and A or B respectively and give to AB and A or B, as the case may be. Main Body The second type of major group is known as Rhesus system of blood group or Rh group because they were first discovered in rhesus monkeys by Karl Landsteiner and Alexander Wiener in 1940. These are another type of antigen found on the surface of the red blood cells. When this type of blood was administered on Rhesus monkeys having Rh positive blood group, complications were developed and agglutination of the blood was observed resulting severe condition of the monkey. This observation led to the landmark discovery of Rh positive and Rh negative types of this blood group. Rh+ meant that humans have Rh factor in their red blood cells and Rh- means that they do not have Rh factor. This type of blood group is much more complex to analyse for a number of reasons. The ABO system of blood group are followed by positive (+) or negative (-) sign signifying the presence or absence of Rh factor in the RBC. “Rh antigens are transmembrane proteins with loops exposed at the surface of red blood cells” (internet). Rhesus system basically comprises of five main antigens known as C, c, D, E and e. The ‘d’ shows the absence of Rh factor. Rhesus system is much more complex than ABO system of blood group because there are more than thirty combinations of antigens on the surface of the blood cell which can be manipulated genetically by two closely linked genes on chromosome 1 which contains DNA information. “Rhesus (or the D antigen) is inherited on one locus, on the short arm of the first chromosome, 1p36.2-p34, with two alleles, of which Rh+ is dominant and Rh- is recessive” (Kromosoft, internet). Genetic conceptualization of Rh factor can be easily made through the two alleles D and d, present at loci on chromosome 1 such that inherited traits and Rh factor be predicted with relative accuracy through the following table; Table 1 (retrieved internet) “Individuals who are homozygous dominant (DD) or heterozygous (Dd) are Rh+.  Those who are homozygous recessive (dd) are Rh- (i.e., they do not have the key Rh antigens)” (internet). Hence, when the first time Rh antigen blood is given to a person with Rh- factor, the transfusion may not show any visible reaction since in the absence of any Rh factor, antibodies produced against the Rh antigen may not show any adverse effects. But when the second time, blood with Rh+ factor is given, the antibodies produced against the Rh antigen from the first instance, would now attack the RBC of fresh blood causing them to agglutinate, resulting in the destruction of red blood cells. This is also known as hemolysis which can even prove fatal. Another significant role of the Rh factor can be seen in the case of erythroblastosis fetalis where the mother may have Rh negative factor (dd) and the father Rh+ (DD) such that the developing fetus would be Rh+ (Dd). In this case, complication would arise due to incompatibility of the blood group of the mother and that of the fetus. The first pregnancy may not be difficult but the second would definitely become dangerous for the mother as well as for the child if proper precautions are not taken. When complications develop, mother’s antibodies may destroy red blood cells of the fetus or placenta endangering the life of the developing life in the womb. The subsequent pregnancies become more dangerous for this heterogeneous coupling because of the fact that the first time labour would have introduced some Rh+ blood of the child into the bloodstream of the mother thereby producing anti Rh antibodies in the mother’s blood. These antibodies would then try to destroy the red blood cells of the fetus in the subsequent pregnancies. The severe repercussions of the condition may result in the new born developing anemia and the lack of adequate oxygen could be life threatening to the child. The erythroblastosis fetalis can be prevented in the women who are at high risk by vaccinating the woman with Rh immunoglobulin or Rho-GAM serum, immediately after the first delivery so that any fetal blood is destroyed before the mother’s blood could make antibodies. The serum contains anti Rh antibodies and provides a passive immunization so that they leave the blood after performing their work of destroying fetal blood. It is preferred that the serum be administered once during the pregnancy (28th week) and then within 72 hours of the delivery. During miscarriage also, the Rh negative woman must be vaccinated. Conclusion It therefore implies that persons with Rh- factor (having no Rh factor on their red blood cells) are more prone to endangering their life during transfusion of blood if necessary precautions are not undertaken in advance. 85% of the world population has Rh factor present in the blood group and 15% of the population has no Rh factor in their RBC. Despite the small population which could have adverse affect because of Rh factor, genetic significance of the Rh factor has not only proved a milestone in the medical history but it has also provided a breakthrough in the child mortality of the erythroblastosis fetalis or Mother-foetus incompatibility cases. It has an extremely vital role in the theory of inheritance because the Rh factor has serious implications in the genetically transferred traits and mutations, which need to be further, investigated. The role of Rh factor in restoring the health of the mother and child is, but the first of the many breakthroughs that our scientists would achieve to improve the quality of human life. Reference Genetics of Rhesus Factor. Kromosoft, promoting Genetics Awreness For a Healthier Society. Accessed from: [25 October 2007]. Rh Blood Types. Accessed from: [25 October 2007]. Blood Groups. Accessed from: [25 October 2007]. Read More