The RH antigen is?

Appeared in: DSSSB - 29 August 2019 (Shift-2)

Explanation

The Rh blood group system's status is primarily determined by the presence or absence of the D antigen on the surface of red blood cells.
The D antigen is the most immunogenic (likely to cause an immune response) of the 50+ antigens in the Rh system, making it the most clinically important.
Individuals who possess the D antigen are classified as Rh-positive (Rh+).
Individuals who lack the D antigen are classified as Rh-negative (Rh-).

Option A: Antigen B is one of the two primary antigens of the ABO blood group system, not the Rh system.
Option C: There is no 'O' antigen. Blood type O is defined by the absence of both A and B antigens on red blood cells.
Option D: Antigen A is one of the two primary antigens of the ABO blood group system, not the Rh system.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Rh blood group system and D antigen as background academic context rather than a clinical decision trigger.
The primary clinical relevance of the Rh system is preventing Hemolytic Disease of the Newborn (HDN). Nurses play a key role in identifying at-risk (Rh-negative) mothers and ensuring the timely administration of Rho(D) immune globulin.
Accurate Rh typing is essential for safe blood transfusions. Administering Rh-positive blood to an Rh-negative recipient can cause sensitization, leading to severe reactions on subsequent exposures.
What if the mother is Rh-positive and the fetus is Rh-negative? In this scenario, there is no risk of Rh incompatibility. The mother's body will not see the fetus's blood as foreign, so no sensitization occurs, and Rho(D) immune globulin is not required.

How to Approach the Question

First, identify the key term in the question: 'RH antigen'.
Recall the two major blood group systems used in clinical practice: the ABO system and the Rh system.
Differentiate the antigens associated with each system. The ABO system is defined by A and B antigens. The Rh system is primarily defined by the D antigen.
Evaluate the options. 'Antigen A' and 'Antigen B' belong to the ABO system, so they are incorrect.
Recognize that 'Antigen O' is not a valid concept; Type O blood is defined by the absence of A and B antigens.
This process of elimination leaves 'Antigen D' as the only correct option associated with the Rh system.

Concept Tested & Keywords

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Practise the full DSSSB - 29 August 2019 (Shift-2)

Attempt every question from this paper in a timed mock, then review the full solution for each one.