Rh Blood Group System

Blood is the main component of our cardiac system. It is the main body fluid that helps to circulate the necessary substances throughout the body. It delivers the nutrients, oxygen & other necessary components to every cell of the body. Now, blood comprises blood cells. There are Red Blood Cells, White Blood Cells, etc. White Blood Cells are responsible for the immune system of the body. Whereas,  Red Blood Cells are responsible for the types of blood groups. These blood groups help us to identify human blood in a very efficient way. Also, these blood groups help us to aware before any blood transplant. So, it is very important to know the blood group systems. These blood groups are divided by the presence of antigens. Antigens are those proteins that are situated above the RBCs. The presence of a particular antigen establishes a particular type of blood.

Types of Blood Group System

There are mainly two types of blood group systems. Combining both will make the complete characteristic of any blood type. These types of blood depend upon the Antigen available on the RBCs. They are:

1. ABO Group System
2. Rh Group System

ABO Group System

The ABO blood group system divides the blood into four types. They are A, B, AB & O types of blood. In A type of blood, there are Antigen A is present. For blood B there are B antigens present. For AB blood there are both A & B types of antigen are present. And for O type of blood there no antigens are present. Now, there is another protein structure which is known as the Antibody. This Antibody is present in the serum of the blood. They are not situated on the surface of RBCs.

Rh Group System

This is the 2nd most significant blood group system. This type of system was first discovered in the 1940s in Rhesus Monkey. There is mainly one Antigen that determines the type of the blood group. The antigen is known as the D antigen. Though there are many other antigens present in the Rh system. But the D antigen plays a major role here. Rh stands for the “Rhesus”.

Discovering the Rh Factor

The Rh factor was discovered through some experiments performed by a group of scientists. They took the RBCs from the Rhesus Monkey & injected those to the blood of small animals like rabbits. They found that those blood reacted to each other & coagulated. Then Scientists found that there is something in the RBCs of the Rhesus Monkey that triggers the antibody of the rabbit to react with each other. This same thing happened to all the monkeys.

Now, the antibodies which developed from the reaction in the rabbit body are injected into the RBCs of the human. They found that in this case also they reacted & coagulated. This means the same thing happened in the case of the monkey. But here, the successful result number is lower. Only 85% of human blood reacted with the antibodies & rest of 15% of blood doesn’t react.

Scientific Reason Behind the Experiment

Scientists later discovered that there are D antigen is present in every RBCs of the Rhesus Money. That antigen is a foreign substance for the blood of the rabbit. That is why it developed the antibodies. Now, while experimenting on human blood they found only 85% of humans had the D antigen in their RBCs. And the other 15% don’t have such. That is why the antibody reacted with only 85% of the sample.

Types of Rh Factor

1. Positive Rh: If the D antigen is present in the RBCs of a human, then it will call as Positive Rh (+ve)
2. Negative Rh: If the D antigen is not present in the RBCs of a human or present in a relatively low quantity, then it will call as Negative Rh (-ve)

What is Antigen & Antibody?

The antigen is a substance that is not available in the blood system of any animal. This substance comes outside of the body. It may be a chemical or pollen or virus etc. This substance comes from the environment. By any means, it mixed with the blood system of the creature. Like via nose some pollen grains can be inhaled. These are so small in dimension that they can easily be mixed up with the blood. Every animal has their own immune system. These substances act as a practical threat to the body of that animal. All such things which act as a potential threat to the immune systems are known as Antigen.

If the immune system discovers such a thing, then it produces antibodies against it. These antibodies help to destroy the Antigen. Like, if any virus infected any human. Then human blood produces Antibody against it. They try to fight against the virus. Hence, it will help the immune system recognize such threats. Again if the same virus is being infected, then it will rapidly produce antibodies against that. Antigens & antibodies are two closely related substances.

Types of Antigens Present in Rh Factor

Scientists discovered till now 50+ antigens in the Rh factor. Though among them only five antigens are important. Among the five antigens, the D antigen is the most important in humans. Important antigens are:

1. D Antigen
2. Capital C Antigen (C)
3. Small C Antigen (c)
4. Capital E Antigen (E)
5. Small E Antigen (e)

Composition of the Rh Factor

Rh factor is not an Anatomical structure. Thus it can’t have a solid structure. It is completely made with protein. It is situated on the surface of the RBCs. It is often called 12 Pass Membrane Protein. As it almost cross the RBC surface 12 times. Thus, it has six curved faces outside of the RBC & six curved faces inside of the RBC. Among them in the first outer curve, their will D antigen present. As this is the strongest antigen that is why it is situated in front of the RBC. The C/c antigens (Capital & Small C) are situated on the second outer curve. And the E/e antigens (Capital & Small E) are situated on the fourth outer curve.

Importance of Rh Factor

The importance of the Rh factor is limitless in science. While donating blood to a patient it is important to know their Rh group previously. Otherwise, there will be a huge problem if some different type of blood is transmitted. Also, it is important that it involve in the development process of the baby in the mother’s womb. Any type of problem that happened with the Rh blood group system can harm the baby. That is why before every operation doctors first take care of the Rh blood group availability. Different types of transplants can cause damage. Also, it is so important that different types of Rh group exposure to an individual body can change his Rh group system.

RHD Polymorphism

Polymorphism is a trait that is inherited from the parents of individuals. Every process which is influenced by inheritance & heredity is known as polymorphism. Polymorphism sometimes acts as a positive function & sometimes acts as a negative function. Polymorphism is a process where the trait of the mother & traits of the father is being combined. After combination a new baby takes birth. As this combination completely happens in a random form, sometimes it causes a problem. This leads to different diseases in a newborn baby. Or sometimes it can lead to a disease in adulthood.

Here, RHD meaning is Rh blood- D antigen. This is also an example of polymorphism. The presence of the D antigen depends upon the nature of the blood group of the father & mother. This is an inherited process. Sometimes combination produces a good trait for the baby & sometimes it is fatal to the baby. If a Rh+ mother & a Rh+ father reproduces a baby then it will be good for the baby. Same if an Rh- mother & an Rh- father reproduces a baby, then also there is no any problem. But the problem happens when the opposite nature of the blood group combines. It leads to a fatal outcome for the baby.

Awareness of Rh Factor

While Transferring Blood

It is quite common practice to provide blood at different blood donation camps. This blood is being conserved for the patients who are in urgent need. But while transferring the blood doctors need to be very careful. Only the same type of Rhesus blood group can able to donate to the same group receiver. This means if the donor is Positive (+ve) & the receiver is also Positive (+ve) from the view of the Rh group then only they can donate blood. But before donating the blood doctor should verify the ABO blood group system also.
If somehow the Positive (+ve) doner provides the blood to the Negative (-ve) receiver then the blood will react with each other & coagulated inside of the body. Hence, the receiver will soon die. The vice versa is also dangerous. So, we have to be very careful in this type of transplantation.

While In the Pregnancy

It is very important to know about the Rh blood group of the baby when it is in the mother’s womb. If the mother & the baby are from the same Rh group then there is no problem at all. But if the Rh group of the mother is the opposite of the baby’s Rh group, then it will be big trouble. Generally, it happens when two different Rh group individuals married each other. If the mother if Positive (+ve) & the baby is Negative (-ve) then this type of problem may arise. The blood of the mother assumes the baby as a foreign substance & starts producing the Anti-D Antigens or Antibodies which will directly affect the baby. So, this is a very concerning moment. The same thing happens for vice versa also.

Hemolytic Disease & History of Disease

Hemolytic Disease is generated in a baby when a Rh+ mother & an Rh- father gives birth to a baby. This can also happen in reverse order also. Like if the mother is Rh- & father is Rh+ then also this type of disease can visualize. The main reason for this disease is that when the Rh factor of the mother is reverse of the Rh factor of the baby, this disease is visualized. In such cases, the mother’s body’s immune system defines the baby as an antigen. It starts producing the antibody against it. Hence, it can damage the growth of the baby.

Hemolytic Disease is a disease most commonly seen in newborn babies. It is first reported in 1609. A French midwife reported hemolytic disease in her twin babies. But as the Rh factor was not invented at that time, doctors can’t identify the disease. Later some more of this type of disease was reported. One is at Boston Children’s Hospital in 1932. This type of disease is very rare. Later when the Rh factor was discovered then scientists can able to recognize the problems related to the babies.

Symptoms of Hemolytic Disease

Hemolytic Disease provides many symptoms. During the pregnancy or after birth it can show the symptoms to the baby. Mainly during the pregnancy period, a bunch of symptoms can observe. Some of them are

1. Anemia can be a symptom during pregnancy. As the RBCs of the baby break down due to the antigen produced from the mother’s blood. The body of the baby can’t able to produce much blood to balance the body. That is why Anemia can be a symptom.
2. Also, as the RBCs break down it will produce a large amount of Bilirubin. This is a yellow color substance. The body of the baby can able to discharge a high amount of Bilirubin. Hence it can cause Hyperbilirubinemia.
3. As the body of the baby tries to produce the blood to make a balance in the body, it will use the Liver & Spleen. The body uses this organ rapidly to produce a high amount of RBCs in a small amount of time. This leads to an enlarged Liver or Spleen.
4. As the Heart can’t work properly due to the lack of blood in the baby. Some organs in the baby build a large amount of fluid in its tissues.

After taking birth the symptoms can also be observed in the body of the baby. During pregnancy, the symptoms developed. After taking birth still, those symptoms can be observed. Some symptoms are:

1. Pale Skin due to the Anemia of the baby.
2. Yellowish skin, eye, etc. due to the process of Hyperbilirubinemia.
3. Enlarged Liver or Spleen due to the process of RBCs rapid production.
4. Severe swelling in the body due to the presence of fluid in the tissues of the body.

FAQs on Rh Blood Group system

Question 1: Do Rh Factors inherited?

Answer:

Yes, Rh factors are inherited from the parents. Like the ABO blood group system, the Rh factor is also determined by the inheritance crossover of the parents. Hence, a blood group of Rh is determined in a baby. It is the same crossover that we find in the sex Gamet crossover.

Question 2: Which blood group is known as the “Universal Receiver”?

Answer:

AB+ blood group is known as the “Universal Receiver”. As in this blood group, all antigens are present. Like A, B & Rhesus antigen (D Antigen) is present. So, they are safe to collect blood from every donor.

Question 3: Which blood group is known as the “Universal Doner”?

Answer:

O- blood group is known as the “Universal Doner”. As in this type of blood, there are no types of antigens are present. A, B & Rhesus antigen (D Antigen) is absent there. So, they are quietly less chance to get any harm while donating their blood to every individual. As there will not be any coagulation problem.

Question 4: What is Golden Blood?

Answer:

Golden Blood is when in the RBCs there is no Rh factor present. Generally, we Rh factor present in less amount than they produce -ve Rh blood. But when there is absolutely zero number of D antigens present in RBCs it is called Golden Blood. Throughout the globe, only 50 persons have Golden Blood.

Question 5: Do all the siblings have the same Rh factors?

Answer:

No, it is not necessary. As it is a crossover between the parents, sometime all the siblings may get the same Rh type. Sometimes, they get different Rh types of blood. It completely depends on the inheritance & the crossover.