Blood bank test 2 ABO
In a bombay what does the typing looks like an O blood group, but serum contains what?
anti-A, anti-B, anti-H
Group O individuals can make what kind of antibody?
anti-A,B
When testing for a subgroup of A look for Degree of agglutination with what?
anti-H
A2 cells will have increased reactivity with what kind of lectin?
anti-H lectin Ulex europaeus
What are ABO subgroups?
phenotypes that differ in the amount of A and B antigen carried on the red cells and present in secretions
What is the procedure for forward typing in ABO typing?
testing the red cells for the presence of the A and/or B antigen using reagent anti-A and anti-B
What is the procedure for reverse typing in ABO typing?
testing the serum/plasma for the presence of ABO antibodies using reagent A1 cells and B cells
True or False: Formation of soluble A, B and H substances same as for that of the RBC with a few changes
True
True or False: Transfusion of a bombay person can only be done with another Bombay blood type
True
True or False: the O allele is nonfunctional?
True
ABH antigens on RBCs are constructed on what kind of chain?
Type 2
What does the genotype of the bombay blood group look like?
hh genotype
L-fucose is what kind of suger?
immunodominant sugar
Soluble ABH antigens can be found where?
in body secretions
In the bombay phenotype a mutation in the H gene, produces a silenced gene which does what?
incapable of coding for the H transferase
In the bombay blood group if no H antigen can formed what else can no be formed?
no A or B antigen can be formed
What are the antibodies that can be found in the serum of a Bombay phenotype?
oAnti-A oAnti-B oAnti-A,B oAnti-H
A allele produces N-acetylgalactosaminyltransferase which transfers N-acetylgalactosamine to what?
oligosaccharide chain
B allele produces D-galactosyltransferase which transfers D-galactose to what?
oligosaccharide chain
What are the Building blocks for A, B and H antigens?
oligosaccharide chain
Designation of group A and B refer to what in genetics?
phenotypes
A1 represents how many A donors that are of European ethnicity?
A1 represents about 80% group A donors among people of European ethnicity
O allele is nonfunctional because the gene product is what?
an enzymatically inactive protein
A1 and A2 both agglutinated strongly by what antibody?
anti-A
What are the possible ABO phenotypes of the offspring from the mating of a group A to a group B individual?
A.O, A, B, AB
What are the two most common sub groups?
A1 and A2
Anti-A1 can sometimes be found in people with subgroups of what blood type?
A
What are the characteristics of the weal ABO subgroups?
-Decreased number ag sites -Variable agglutination with anti-A,B -Variable detection of anti-H -Anti-A1 may or may not be present
What percentage of European ethnicity have the subggroup A2
20%
When do naturally occuring ABO antibodies occur?
3-6 months of age and peaks at age 5-10 years
What do the oligosaccharide chain comprise of?
4 sugar molecules in linear form
Enzymes studies comparing A1 and A2 glycotransferase activity show A1 enzyme is more __________ than A2
5-10 times more active than A2
H antigen is the precursor for what antigens?
A and B antigens
L-fucose is an immunodominant sugar that is a critical step in the formation of what?
A and B antigens
An ABO type on a patient gives the following reactions: Patient cells with: Patient serum with: Anti-A: 4+ Anti-B: 4+ A1 Cells:neg B Cells:neg What is the patient's blood type?
AB
Se gene determines the soluble expression of what antigens?
ABO antigens
Formation of A, B and H Soluble Antigens are dependent on what?
ABO genes inherited and the secretor genes (Sese)
Inheritance and formation of ABH antigens result from interaction of genes located where?
ABO, Hh and Se loci
What does o negative look like?
Anti-A=0 Anti-B=0 Anti-D= 0+ A1 cells=4+ B1 cells=4+
What does o positive look like?
Anti-A=0 Anti-B=0 Anti-D= 4+ A1 cells=4+ B1 cells=4+
What does B negative look like?
Anti-A=0 Anti-B=4+ Anti-D= 0+ A1 cells=4+ B1 cells=0+
What does B positive look like?
Anti-A=0 Anti-B=4+ Anti-D= 4+ A1 cells=4+ B1 cells=0+
What does bombay look like?
Anti-A=0+ Anti-B=0+ A1 cells=4+ B1 cells=4+ o cells=4+
What does A negative look like?
Anti-A=4+ Anti-B=0 Anti-D= 0+ A1 cells=0+ B1 cells=4+
What does A positive look like?
Anti-A=4+ Anti-B=0 Anti-D= 4+ A1 cells=0+ B1 cells=4+
What does AB negative look like?
Anti-A=4+ Anti-B=4+ Anti-D= 0+ A1 cells=0+ B1 cells=0+
What does AB positive look like?
Anti-A=4+ Anti-B=4+ Anti-D= 4+ A1 cells=0+ B1 cells=0+
What does Anti-H do?
Anti-H is a potent hemolysin capable of binding complement
What is the rarest blood type?
Bombay
Red cells from hh individual are what kind of phenotype?
Bombay phenotype
B allele produces what kind of sugar?
D-galactosyltransferase
When testing for a subgroup of A looking for the degree of agglutination with anti-A is possibly by using what?
Dolichos biflorus
When testing for a subgroup of A: Look for the degree of agglutination with anti-A and possibly what?
Dolichos biflorus
What are the two components in Routine ABO Typing
Forward Reverse
H is the only antigen of which blood group system?
H blood group system
Where is the mutation found in the bombay phenotype?
H gene
What is the predominant antibody in the O blood group?
IgG
The predominant immunoglobulin class(es) of anti-B in a group A individual is (are):
IgM
What is the predominant antibody in the A and B blood group?
IgM antibody
Genes encode for glycosyltransferase, L-fucosyltransferase to add what to what?
L-fucose to terminal sugar of type-1 or -2 chain
The immunodominant sugar responsible for blood group A specificity is:
N-acetyl-D-galactosamine
the A allele produces what kind of suger?
N-acetylgalactosaminyltransferase
What is the most common blood type
O
What does the bombay phenotype look like written out?
Oh
How is the phenotype determined in a routine ABO typing test?
Phenotype is determined when red cells are directly tested for the A and/or B antigen
Routine ABO Typing is what kind of genetic testing?
Phenotyping
What kind of gene is the bombay phenotype?
Rare autosomal recessive phenotype
How are Weaker subgroups of A and B recognized?
Recognized due to ABO discrepancies
Does the ABO blood group system follow Mendelian genetics?
Yes
Both IgM and IgG can do what to RBC's?
agglutinate RBCs at RT
How does the MLS distinguish between the A1 and A2 sub group?
by using the lectin Dolichos biflorus
How is the Bombay phenotype characterized?
characterized by the absence of H, A, and B antigens on RBCs and in secretions
What kind of expression is the ABO blood system?
codominant
Both IgM and IgG can efficiently activate what?
complement
What kind of gene is the O gene in the ABO blood group system?
considered an amorph and autosomal recessive
When do ABO antigens develop
early in fetal life (5 to 6 weeks of Gestion)
h is an amorph with no detectable what?
gene product
AA, AO, BB, BO, AB, OO are considered as what in genetics?
genotypes
Three major alleles in ABO controlled by what?
glycosyltransferases
Genes do not code for ag production but for specific what?
glycotransferases
What are affected by ABO subgroups?
those who are secretors
True or False: Weaker subgroups of A and B have been Infrequently encountered
true
How does the bombay blood group happen?
two little h's
Which sub group is more common A or B
§A subgroups are more common that B subgroups
When testing for a subgroup of A what are all the things a MLS should be looking for?
ØLook for the degree of agglutination with anti-A and possibly Dolichos biflorus ØDegree of agglutination with anti-A,B ØDegree of reactivity with anti-H ØAdsorption and elution studies for very weak subgroups ØFamily (pedigree) studies ØMolecular testing
What are the antibodies for the ABO group?
•Anti-A and Anti-B
Red cells from hh individual are the phenotype for which blood group?
•Bombay phenotype
What are the two significant alleles of the H blood group system?
•H and h
Which gene is dominant in the H blood group system?
•H is dominant with frequency of 99.99%
What do ABO antibodies do?
•Produced against the antigen that the individual lacks on their own RBCs
Which gene an amorph in the H blood group system?
•h is an amorph with rare frequency
Inheritance of Se gene codes for production of what?
∂-2-L-fucosyltransferase
