ABO BLOOD GROUP SYSTEM Flashcards
● most important system in transfusion and transplantation therapy
ABO BLOOD GROUP SYSTEM
only blood group system in which individuals have antibodies in their serum to antigens that are absent from their RBC
ABO BLOOD GROUP SYSTEM
discovered ABO blood group system in 1901
Karl Landsteiner
the first one to perform the forward and reverse blood
typing.
Karl Landsteiner
genetic makeup of an individual
Genotype
physically manifested/physical characteristics of an
individual
Phenotype
two subgroups of A
A1 (80%) and A2 (20%)
WHAT IS YOUR GENOTYPE if you are O
O
Genotype: if B
BB / BO
T or F: A1 is more dominant than A2
True
T or F: A and B genes are codominantly expressed
True
T or F: A and B genes are more dominant than O gene
True. When you combine O with A and B, O will not be
expressed. Only A and B genes will be expressed phenotypically
ABO genes are located on what chromosome?
Chromosome 9
used to show the codominant manner of
inheritance of the ABO blood group system
Punnett square
Are inherited in a codominant manner following simple Mendelian genetics laws
ABO GENES
A, B, and H Antigens are expressed on
Surface of RBC
H gene
Glycosyltransferase:
Immunodominant sugar:
Glycosyltransferase: L- fucosyltransferase
Immunodominant sugar: L-fucose
A gene
Glycosyltransferase:
Immunodominant sugar:
Glycosyltransferase: N-acetylgalactosaminyl-transferase
Immunodominant sugar: N-acetyl-D-galactosamine
B gene
Glycosyltransferase:
Immunodominant sugar:
Glycosyltransferase: D-galactosyltransferase
Immunodominant sugar: D-galactose
attachment of immunodominant sugars
occurs on the RBC membrane and it is dependent on ABH genes inherited.
37th day of fetal life
These antigens are not fully expressed until about
2-4 years of age
Compositions of the paragloboside:
○ Glucose
○ Galactose
○ N-acetylgalactosamine sugar
○ Terminal galactose
Sugars in type O individuals
Antigens under ABO are found on the
RBC membrane
ABO antibodies are predominantly and react at what temperature?
Igm, react at room temperature/ambient/cold
using known sources of commercial antisera (anti-A, anti-B) to detect antigens on an individual’s RBCs.
Forward grouping
defined as detecting ABO antibodies in the patient’s serum by using known reagent RBCs, namely A1 and B cells.
Reverse grouping
can be performed using the slide method or the tube
method.
Forward grouping
also known as serum typing or back typing.
Reverse grouping
Anti-A (blue): dye
Anti-B (yellow): dye
Anti-A (blue): TRYPAN BLUE
Anti-B (yellow): ACRIFLAVINE
T/F:
I. Always drop the clear solution first then followed by the colored solution or RBCs.
II. If the antisera is dropped first, it is because they do not want you to contaminate the antisera.
Both true
Regulates the formation of H antigen and subsequently, of A and B antigens in secretory cells
Sese system (secretor)
Are regulatory genes that will control the formation
of H antigens in the secretions in the erythrocytes.
Zz and Se genes
TorF:
You can’t used saliva as a back-up specimen for blood typing in case there are ABO discrepancies.
False
In red cells, epithelium tissues, BM, other cells
Glycolipids
Glucose Type 2
1 → 4 linkage
FUT1 (Zz gene)
ABH Antigens