Common Blood groups Flashcards
At what temperature do Duffy antigens optimally react?
37°C
The reactive phase for Duffy antigens is typically observed at this temperature using AHG.
What enzymes can destroy Duffy antigens?
Papain, ficin, trypsin, bromelain
These enzymes are used in blood typing to assess the presence of Duffy antigens.
What is the frequency of Fy(b) antigen in the Caucasian population?
80%
Fy(b) antigen was first identified in 1951 and is prevalent in Caucasians.
What type of antibodies are frequently seen in the Black population concerning the Duffy system?
Anti-Fy(a) and Anti-Fy(b)
These antibodies often arise from multi-transfusions and can lead to delayed hemolytic transfusion reactions.
What class of antibodies is associated with the Kidd Blood Group System?
IgG
These antibodies are clinically significant and react optimally at 37°C.
What immunoglobulin class is associated with anti-Lu(a)?
IgM and IgG
Most examples of anti-Lu(a) are IgM and may occur without prior RBC stimulation.
What is the optimal reaction temperature for anti-Lu(b)?
37°C
Most reactions for anti-Lu(b) occur during the indirect antiglobulin test.
What is the main antigen in the P Blood Group System?
P1 antigen
The P blood group system also includes Pk and Luke antigens.
What is unique about the P1 and P2 phenotypes?
P1 phenotype has both P and P1 antigens; P2 phenotype has P antigen only
80% of individuals with P antigen are P1 phenotype.
What is autoanti-P associated with?
Paroxysmal Cold Hemoglobinuria (PCH)
It binds to antigens on the patient’s red cells in cold temperatures and causes hemolysis at 37°C.
What is the Donath-Landsteiner test used for?
To confirm the presence of anti-P antibodies
It tests for hemolysis at specific temperatures.
Are I and i antigens antithetical?
No
I and i are not antithetical antigens.
Where can I and i antigens be found as soluble glycoprotein Ag’s?
In plasma and body secretions
Examples include amniotic fluid and breast milk.
What is the most commonly encountered autoantibody?
Anti-I
Using cord cells aids with identification.
What temperature enhances the reactivity of the I autoantibody?
Colder temperatures
Testing at 4ºC aids in confirmation of the presence of the antibody.
What is associated with strong autoanti-I?
Mycoplasma pneumoniae infections and cold hemagglutinin disease
Anti-i is associated with infectious mononucleosis and lymphoproliferative disease.
What type of antibody is anti-I?
IgM
It is poorly developed in infants and is not associated with hemolytic disease of the newborn (HDN).
What happens in reverse grouping when anti-I is present?
All results are positive
A1 and B cells always agglutinate, reversing results as group O.
What technique can correct forward typing affected by autoanti-I?
Washing cells in warm saline and re-testing
Correcting reverse grouping involves serum prior to testing.
What is anti-IH directed against?
Both I antigens and H antigens
It reacts most strongly with group O adult cells.
What are the reactions of Anti-I, Anti-IH, and Anti-H with adult A cells?
Anti-I: 2+, Anti-IH: 2+, Anti-H: 0
These reactions vary with other cell types.
Is anti-i clinically significant?
No
Auto-anti-i is rare and gives weaker reactions with I RBCs.
What are the serological characteristics of HTLA antibodies?
IgG, weak positive to 1+ reactions
They react optimally after 37°C incubation and are inconsistent.
Do HTLA antibodies cause hemolytic transfusion reactions?
No
They are not clinically significant and may mask clinically significant antibodies.
