Unit 3 Flashcards
What is the most significant blood group system in transfusion and transplant medicine?
ABO blood group system
ISBT Number 001
Who discovered the ABO blood group system and in what year?
Karl Landsteiner in 1901
What is Landsteiner’s Rule?
Normal, healthy individuals possess ABO antibodies to the ABO blood group antigens absent from their red cells.
What is forward grouping?
Use of known sources of commercial antisera to detect antigens on an individual’s RBC.
What is reverse grouping?
Detecting ABO antibodies in the patient’s serum using known reagent RBCs, namely A1 & B cells.
What type of antibodies are ABO antibodies, and when do they predominantly react?
Naturally occurring IgM that reacts at room temperature (20-24˚C) or colder.
At what age does the peak of antibody production occur for ABO antibodies?
5-10 years old.
What are the types of ABO antibodies?
- Anti-A
- Anti-B
- Anti-A,B
What is the immunodominant sugar for A1 and A2 subgroups?
N-acetyl-D-galactosamine
What is the difference in reactivity between A1 and A2 subgroups?
A1 reacts with both Anti-A & Anti-A1; A2 reacts with Anti-A but not Anti-A1.
What is a characteristic of weak A subgroups?
Decreased number of A antigen sites per red cell results in weak or no agglutination with commercial anti-A reagents.
List the classifications of weak A subgroups.
- Aint
- A3
- Ax
- Am
- Aend
- Ael
- Abantu
What distinguishes weak B subgroups?
Variations in reaction strength using anti-B and anti-A,B.
List the classifications of weak B subgroups.
- B3
- Bx
- Bm
- Bel
True or False: 99% of group A individuals are either A1 or A2.
True
What is the role of Ulex europaeus in relation to the ABO groups?
Describes the reactivity of Ulex europaeus with various ABO groups.
What are the weak subgroups of A?
A3, AX, Aend, Am, Ay, Ael.
Explain the effects of disease on ABH antigens and antibodies.
Disease can affect the expression of ABH antigens and antibodies.
What is the significance of the inverse reciprocal relationship in blood typing?
One serves as a check on the other between forward and reverse typing.
Fill in the blank: Anti-A1 is produced by ________ of A2 individuals.
1% to 8%
Fill in the blank: The detection of antibodies occurs at ________ months.
3-6
