ABO Flashcards
Exam 1
An individual with type A blood will have which ABO antibodies present?
Anti-B
An individual with type B blood will have which ABO antibodies present?
Anti-A
An individual with type O blood will have which ABO antibodies present?
Anti-A, Anti-B, and Anti-A,B
An individual with type AB blood will have which ABO antibodies present?
None
Describe the process of performing a forward grouping
Add 1 drop of reagent (anti-A, B, or D), add 1 drop of a 3-5% patient RBC suspension, centrifuge for 30 seconds, and read
Describe the process of performing a reverse grouping
Add 1 drop of A1 or B cells, add 2 drops of patient plasma, centrifuge for 30 seconds, and read
The forward grouping is detecting patient _________________.
Antigens
The reverse grouping is detecting patient _________________.
Antibodies
What are the frequencies of the different blood types?
O: 45% A: 40% B: 11% AB: 4%
Are ABO antibodies natural or immune antibodies?
Natural
Are ABO antibodies usually IgM or IgG?
IgM
At which temperature do ABO antibodies react best?
Room temperature or colder (4C- 24C)
Can ABO antibodies cause hemolytic transfusion reactions and hemolytic disease of the fetus and newborn?
Yes
Describe the strength of ABO antibodies throughout life.
Birth: initiate antibody production- undetectable. 3-6 months: titers are strong enough to be detected. 5-10 years: antibodies are at their peak strength. Increasing age: antibody titers decline. Elderly: antibodies may entirely disappear
If an individual is type A, what possible genotypes could they have inherited?
AO or AA
Which gene in the ABO blood group system is an amorph and which gene in the Hh blood group system is an amorph?
ABO: O, Hh: h
The ABO and H genes produce what kinds of enzymes and what do these enzymes do?
Produce glycosyltransferases which add sugars to a precursor substance
Describe the difference between type 1 precursors and type 2 precursors.
Type 1: beta 1-3 linkage, found as soluble antigens in body secretions. Type 2: beta 1-4 linkage, found on red cells.
For an individual to be group O, what genes must they have inherited?
At least 1 H gene and 2 O genes
Which enzyme does the H gene produce?
a-2-L-fucosyltransferase
What is an immunodominant sugar?
The sugar at the terminal position of the antigen determining the blood group
What is the immunodominant sugar for group O?
L-fucose
Which antigen must be present on the precursor chain before A or B can attach?
H antigen
For an individual to be group A, what genes must they inherit?
At least one A gene and one H gene
Which enzyme does the A gene produce?
a-3-N-acetylgalactosaminyltransferase
What is the immunodominant sugar for group A?
N-acetyl-D-galactosamine (GalNAc)
For an individual to be group B, what genes must they inherit?
At least one B gene and one H gene
Which enzyme does the B gene produce?
a-3-d-galactosyltransferase