Unit 3: The ABO and Rh Flashcards
Who discovered the ABO blood system and when?
1902 Karl Landsteiner
What age do you see naturally occurring antibodies to the ABO antigens they lack?
people older than 3-6 months of age
What did Landsteiner demonstrate?
a person’s serum contains naturally occurring antibodies to an antigen you don’t have
What are the Landsteiner rules?
If the ABO antigen is present on the cells, the corresponding antibody will be absent in serum
If the ABO antibody is present in the serum, the corresponding antigen will be absent on the cells
If you have B or A antigen present, what do you lack?
antibody B or A
Blood type O has no ___ but _____
antigen A or B but both antibodies A and B
Blood type AB has what antigens/antibodies present?
Both antigens A and B but no antibodies
Incompatible ABO transfusion results to…
acute intravascular hemolysis
renal failure
fatality
ABO reagents made from ___ are not often used due to problems with nonspecificity
human serum
ABO typing reagents are made from….
monoclonal antibodies
What are the lectins used in blood banking?
Dolichos biflorus (A1 or A1B cells) Bandeiraea simplicifolia (B cells) Ulex europaeus (O cells, H specificity)
What are the ABO reagent colors?
Anti-A is blue
Anti-B is yellow
Anti-A1B & Anti-H are colorless
What does forward typing test for?
antigens (patient RBCs) using antisera
What does reverse typing test for?
antibodies (patient serum) with reagent RBCs
What is antisera?
reagents with known ABO antibodies
What is the least common ABO phenotype?
AB
What is the most common ABO phenotype?
O
What antibody class is IgG only?
Anti-A,B
Which population has the highest frequency of O blood phenotype?
Hispanics
Which population has the highest frequency of A blood phenotype?
Caucasians
Which population has the highest frequency of B blood phenotype?
African Americans
Which population has the highest frequency of AB blood phenotype?
Asians
When do antibody productions peak?
5-10 years of age
What is antibody A,B?
a cross reacting antibody that can’t be dissociated
What chromosome is occupied by A, B or O gene?
9
Which gene is considered amorph?
O
Phenotypes Vs. Genotypes
A or B vs. AA, BB, OO
The formation of ABH antigens results from…
the interactions of the genes at 3 separate loci
What do the ABO, Hh and Se genes code for?
to produce specific glycosyltransferases that add sugar to a basic precursor substance to make the ABH antigens
What are the type 2 precursor substances?
ABH antigens (attached to paragloboside or glycan)
Where are the type 1 precursor chains found?
body fluids, milk, plasma, urine and tears
Where is the H gene located?
chromosome 19
The amount of H antigen you have is based on…
How much sugar is added to it
What antigen will have the most H antigen?
O
If the chain only presents with fucose, what blood cell type do you have?
O
If the chain presents with fucose and GalNAc , what blood cell type do you have?
A
If the chain presents with fucose and D-galactose, what blood cell type do you have?
B
ABH soluble substances are based on ABO genes inherited and another set of genes called…
Sese (secretor genes)
The secretor gene only plays a rolf in what precursor type?
I
What is an ABO subgroup?
differs in the amount of antigen carried on red cells