Problem 36 - Objective Biology for NEET

Question

In case of emergency, which blood group could be safely transfused? (a) \(\mathrm{AB} \mathrm{R}-\) (b) \(\mathrm{AB} \mathrm{Rh}+\) (c) \(\mathrm{O} \mathrm{Rh}-\) (d) \(\mathrm{O} \mathrm{Rh}+\)

Step-by-Step Solution

Answer

The blood type that can be safely transfused in case of an emergency is \(\mathrm{O} \mathrm{Rh}-\).

Step 1: Understand Blood Group Compatibility

Different blood groups have different antibodies and antigens. For blood transfusion, the donor's blood should not have such antigens that the recipient's blood would attack. Type O blood is known as the universal donor since it lacks A and B antigens, hence, it can be donated to any blood group. Similarly, Rh- lacks Rh antigen and can be donated to both Rh+ and Rh-.

Step 2: Identify the Universal Donor

Based on the above understanding, the blood group that can be safely transfused in case of emergency would be the one which is considered as the 'universal donor', which lacks any antigens that could be attacked by recipient's body.

Step 3: Answer based on Understanding

Given the options (a) AB Rh-, (b) AB Rh+, (c) O Rh-, and (d) O Rh+, it can be deduced that the O Rh- blood group can safely be transfused because it lacks A, B and Rh antigens and hence will not be attacked by the recipient's body, regardless of their blood type.

Key Concepts

Blood Group Compatibility

Understanding blood group compatibility is critical when it comes to blood transfusions because it can be the difference between a lifesaving procedure and a life-threatening reaction. Each blood group has specific antigens present on the surface of their red blood cells and antibodies in the plasma. The ABO and Rh systems are the most important for blood transfusions.

In the ABO system, there are four main blood types: A, B, AB, and O. Types A and B have their respective antigens on the cell surface, Type AB has both, and Type O has none. If you introduce blood with A antigens to a person with B antigens (or vice versa), their body will recognize these as foreign and unleash an antibody attack. Consequently, for a transfusion to be successful, the donated blood must be compatible; otherwise, it can lead to an immune response that could be fatal.

Type O blood is called the universal donor, specifically the O Rh- type, because it lacks A, B, and Rh antigens, making it less likely to be rejected by the recipient's immune system.

Blood Transfusion

A blood transfusion is a routine medical procedure in which donated blood or components of blood are transferred into a recipient's bloodstream. It is performed to replace blood lost during surgery, to treat anemia when the body doesn't produce enough red blood cells, or to treat various other conditions.

For a successful blood transfusion, health professionals must ensure blood group compatibility. The key to compatibility is the presence or absence of specific antigens and antibodies. If incompatible blood is transfused, the recipient's immune system may attack the donor red blood cells, leading to transfusion reactions. These reactions can be mild or severe, and in some cases, even life-threatening. Therefore, a thorough cross-match test is done beforehand to ensure compatibility.

Furthermore, before administering the transfusion, the universal donor blood, O Rh-, is considered the safest choice in emergencies due to its broad compatibility with other blood types.

Rh Factor

The Rh factor, or Rhesus factor, is another crucial element in blood transfusions, closely linked to blood group compatibility. Rh factor is a specific protein found on the surface of red blood cells. You are considered to have Rh+ blood if this protein is present and Rh- if it is absent.

If a person with Rh- blood receives Rh+ blood, their body might produce antibodies against the Rh factor, leading to complications. Therefore, Rh compatibility is just as important as ABO compatibility. The Rh- blood is especially important because it can safely be given to Rh- and Rh+ individuals, making Rh- donors very valuable particularly, the O Rh- blood type which is universally compatible.

The concept of Rh factor comes into play not only in transfusions but also during pregnancy. If an Rh- mother carries an Rh+ baby, her body might produce antibodies against the baby's RBCs, a condition known as hemolytic disease of the newborn. Consequently, understanding and managing Rh factor compatibility is vital for safe blood transfusions and maternal care.