LA3 Rh Blood Group System Flashcards
How is “Rh positive” different from “Rh negative”?
Determined by whether or not the patient has the D antigen.
Why is D antigen the most important in the Rh Blood Typing System?
It is the most immunogenic - causes antibodies to be formed.
How many patients exposed to D-antigen will make anti-D antibodies?
50-70%
Why is Rh testing done in duplicate?
1) to confirm Rh is correct
2) don’t have “reverse typing” for Rh
What is “Rh control” reagent?
Diluent control that contains all ingredients of anti-D except actual anti-D antibodies.
Why do we need “Rh control”?
To make sure a positive result isn’t a false positive due to the red cells reacting with the reagent additives or diluent.
When is false positive Rh especially likely?
If RBCs are presensitized with antibodies of any kind.
What result is expected from diluent control in Rh typing?
Diluent control should always be negative.
What is to be done if Rh control produces positive result?
Tests can’t be interpreted and further testing is required.
What is anti-D minimum reaction for a positive conclusion?
2+
What are 5 main antigens in Rh system?
D, C, E, c, e
What would be classical reaction pattern for an Rh negative person to 5 main antigens in Rh system?
–D : 0 ; –C : 0 ; –E : 0 ; –c : + ; –e : +
How is Rh antibodies’ production stimulated?
Mostly, by pregnancy or transfusion.
What kind of antibodies are Rh antibodies?
IgG
How is the detection of Rh antibodies enhanced in vitro?
By use of antibody potentiators
