Table of Contents
Why is the D antigen so important?
The D antigen is the most immunogenic, meaning it provokes an immune response that makes it most likely to cause a transfusion reaction in the recipient.
What blood type has D antigens?
People with the Rh+ blood group have D antigens on the surface of their red blood cells, while Rh- individuals do not.
What does D mean in blood type?
The D antigen in the Rh system determines whether you have positive or negative blood. If you have the Rh D antigen, your blood type is positive. If you lack the Rh D antigen, your blood type is negative. 77\% of our donors are Rh D positive. There are four other main antigens in the Rh system.
What is D antibody?
Anti-D is a powerful antibody that protects babies from Rhesus D Haemolytic Disease of the Foetus and Newborn, or HDN, a disease in which a mother’s body creates an antibody that destroys her unborn child’s red blood cells. HDN can cause anaemia and jaundice leading to heart failure, brain damage and still birth.
What causes weak D antigen?
Red cells that carry weak forms of D antigen are classified as “weak D,” which usually results from amino acid substitutions within the internal portion or in the membrane-crossing portion of the RhD protein causing quantitative changes.
What causes weak D?
Weak D and partial D expression are caused by a large number of RHD alleles and variations of the antigen structure of RhD result either in a partial (partial D) or a weak D phenotype (weak D). Weak and partial D result in quantitative and qualitative changes in Rh protein expression respectively.
What does weak D antigen mean?
Weak D antigen is a phenotype where the D antigen is weakly expressed on red blood cells, and this antigen cannot be detected by routine methods.
Is RhD positive bad?
If your next baby is Rh positive, these Rh antibodies can cross the placenta and damage the baby’s red blood cells. This could lead to life-threatening anemia, a condition in which red blood cells are destroyed faster than the baby’s body can replace them.
What does a rhesus D positive mean?
If you’re rhesus positive (RhD positive), it means that a protein (D antigen) is found on the surface of your red blood cells. Most people are RhD positive. If you’re rhesus negative (RhD negative), you do not have the D antigen on your blood cells.
How do you get Anti-D antibodies?
This can happen if the baby’s father is RhD positive. The problem can occur if a small amount of the baby’s blood enters the mother’s bloodstream during pregnancy or birth, the mother can produce antibodies against the rhesus positive cells (known as ‘anti-D antibodies’).
Is Weak D antigen bad?
The risk of alloimmunization remains if weak D antigen positive blood is transfused to Rh D-negative individual. This becomes a major concern if the recipient is of childbearing age and can result in hemolytic disease of the newborn in subsequent pregnancy.