ABO blood group intro Flashcards
Who discovered the ABO blood group system?
Karl Landsteiner
What is being detected in reverse grouping?
Antibody
What antigen serves as the precursor structure on which A and B antigens are made?
H antigen
What is/are the antigen/s present in a group B individual?
B antigen
What is/are the antibody/ies present in a group O individual?
Anti-A/Anti-B
What is the most important blood group system in transfusion and transplantation therapy?
ABO blood group system
ISBT terminology for Rh blood group
004
meaning of ISBT
International Society of Blood Transfusion
What was the original name of blood type O?
Blood type C
Why was blood type C changed to O?
To avoid confusion with the existence of a ‘C’ antigen
What is the ISBT terminology for the ABO blood group?
001
What are the two types of ABO testing?
Forward typing and reverse typing
most frequently performed test in blood bank
ABO testing
What is the universal donor for RBC transfusions?
Type O
What is the universal recipient for RBC transfusions?
Type AB
What is the universal donor for plasma transfusions?
Type AB
What is the universal recipient for plasma transfusions?
Type O
What is the unique characteristic of Anti-AB?
It cannot be separated
Which blood type is given in emergencies due to the absence of A, B, and D antigens?
Type O, Rh (-)
Who discovered blood type AB?
Adriano Sturli & Alfred von Decastello
What does forward typing determine?
unknown antigen using known antibody
What does reverse typing determine?
unknown antibody using known antigen
Why is reverse typing not performed on babies?
They lack antibodies at birth
Which blood type is associated with gastric carcinoma?
Type A and Type AB
Which blood type is associated with ulcers?
Type O
Which blood type is linked to criminality?
Type B
When do ABO antibodies begin to appear in infants?
Between 3 to 6 months of age
When do ABO antibody levels peak?
Between 5 and 10 years of age
Why do elderly individuals have lower levels of ABO antibodies?
may be due to thymus atrophy
What type of immunoglobulin are most ABO antibodies?
Predominantly IgM
What immunoglobulin is unique to Anti-AB?
IgG
most common blood type
type O
used as control in reverse typing
O cell
What is the function of the H gene?
responsible for antigen presence on RBC surface
What is the function of the Se gene?
responsible of antigen presence in secretions
Most antibodies in cord blood serum are of __ __ (IgG)
maternal origin
What is a homozygous genotype?
An individual has two identical alleles for a trait
What is a heterozygous genotype?
An individual has two different alleles for a trait
Which blood group antigen develops first in fetal life?
H antigen
When are ABO antigens fully developed on RBCs?
By 2 to 4 years of age
What is the Bombay phenotype?
A rare condition where an individual lacks H antigen (hh genotype)
what year was the ABO inheritance first described
1924
Which sugar is responsible for H antigen specificity?
L-fucose
What sugar is added to the H antigen to form A antigen?
N-acetyl-D-galactosamine
What sugar is added to the H antigen to form B antigen?
D-galactose
A gene that does not produce a detectable antigen
amorph gene
gene that is always expressed
dominant gene
can agglutinate human RBCs with specificity but are not AB
lectin
Which enzyme is responsible for adding L-fucose to the precursor chain?
L-fucosyltransferase
What is the function of the HLA typing in transplantation?
To ensure organ compatibility with the recipient’s tissues
What type of linkage is found in Type 1 precursor chains?
Beta 1→3 linkage
What type of linkage is found in Type 2 precursor chains?
Beta 1→4 linkage
Which antigen is always present in secretors?
H antigen
How can the presence of ABH antigens in saliva be tested?
Agglutination inhibition test
What is the significance of the agglutination inhibition test?
It determines whether a person is a secretor or non-secretor
Which bodily fluids contain ABH soluble substances?
Saliva, tears, urine, digestive juices, bile, milk, amniotic fluid, peritoneal fluid, pleural fluid
lectin is from __ __
griffonia simplicifolia
provides the probable phenotype from known genotypes
punnett square
who discovered the punnett square
dr. reginald punnett
immunodominant sugar of type A
N-acetyl-D-Galactosamine
immunodominant sugar of type B
D-galactose
immunodominant sugar of type AB
N-acetyl-D-Galactosamine & D-Galactose
phenotypic expression may vary with (3)
race
genetic interaction
disease states
enzyme that destroys N-acetyl branch in acquired B phenomenon
D-acetylase
Sugars occupying the terminal positions of the
precursor chain
immunodominant sugars
Must be formed for the other sugars to be attached in response to an inherited A and/or B gene
L-fucose
lacks normal expression of ABH antigens
bombay phenotype
t/f: B enzyme seems to compete more efficiently for the H substance than the A enzyme
t
a antigens on an AB cell: __ sites
600,000 sites
b antigens on an AB cell: __ sites
720,000 sites
tissue blood group
ABO blood group
transplantation will occur only if HLA + ABO compatible. if there is a mismatch, __ __ will occur
rejection reaction
Codes for the production of α-2-L-fucosyltransferase
Se gene
t/f: all nonsecretors are bombay
f
positive result in agglutination inhibition
without agglutination
RBC antigens can be __,
__, or __
glycolipids, glycoproteins, glycosohingolipids
Secreted substances are __
glycoproteins
RBC antigens are synthesized only on __ precursor chains
type 2
Secreted substances are primarily
synthesized on __ precursor chains.
type 1
Types 1 and 3 chains: associated with __
body secretions
Types 2 and 4 chains: associated with __
RBC membrane
test done to determine genotype
DNA testing
test done to determine phenotype
serological test
recessive or dominant: o gene
recessive
Basic precursor material from which A, B, and H antigens originate
paragloboside / glycan
returns lost N-acetyl to D-galactose in acquired B phenomenon
acetic anhydride
