ABO BLOOD GROUP Flashcards
Most important of all blood groups in both transfusion and transplant medicine.
ABO System
The only blood group system in which individuals already have antibodies in their serum to antigens that are absent from their red blood cells
ABO system
these are substances that are recognized by the body as something foreign which can cause an immune response
Antigens
Antigens cause an immune respons to?
Bacteria, viruses or anything that the body will recognize as foreign
where are antigens found?
usually found on the membrane of the red blood cell
where are antigens found?
usually found on the membrane of the red blood cell
are substances produced by the body in response to the antigen or the foreign substance that was detected by the body.
Antibodies
how are antibodies developed?
when we are exposed to antigens
Occurs without any prior exposure to red blood cells through blood transfusion or pregnancy
Antibodies
how does an antibody occur naturally?
Through blood transfusion or pregnancy
what happens when antibodies aren’t compatible?
may result in immediate lysis of donor red blood cells
meaning the wrong blood type was
transfused to the patient.
incompatible
lysis is also another term for?
destruction of red blood cells
Why will there be lysis or destruction of red blood cells? (state the three reasons)
o Because of the antibodies present in the patient or recipient.
o As mentioned, antigens present from the cell of the donor will be recognized as foreign to the patient.
o Antibodies of patients will attack the red blood cells of the donor transfused because of the incompatibility.
Transfusion of the wrong ABO blood group remains the leading cause of death in _____________.
hemolytic transfusion reaction fatalities
he discovered the ABO Blood group system in the 1900s
Karl Landsteiner
what did Karl Landsteiner discovered and when was it discovered?
ABO Blood group system during 1900s
He classified an individual’s erythrocytes into 4 types: Blood Types A, B, AB, and O
Karl Landsteiner
How did Karl Landsteiner classified the erythrocytes?
Blood Types A, B, AB and O
His classification marked the beginning of the
concept of individual uniqueness defined by the RBC antigens present on the RBC membrane
Karl Landsteiner
Karl Landsteiner marked the beginning of the
concept of individual ______ defined by the _________ present on the RBC membrane
uniqueness, RBC antigens
_________ are found on the membrane of red blood cells.
RBC Antigen
_________ are found on the membrane of red blood cells.
RBC Antigen
is present on the red blood cell membrane. What is it specifically what antigen?
Agglutinogen
where is agglutinogen present ?
present on the red blood cell membrane
it is under landsteiner’s law where it is absent in the plasma. What is it?
Aggluntinin
where is agglutinin absent and present?
absent in the plasma if agglutinogen is present, while it is present if agglutinogen is absent
what did landsteiner’s law stated?
If an agglutinogen (antigen) is present on the red blood cell membrane, the corresponding agglutinin (antibody) must be absent in the plasma
Ifan agglutinogen isabsent on the red blood cell membrane, the corresponding agglutinin must be present in the plasma or serum
what happens when antigen and antibody interacts?
Result into agglutination or clumping of the RBCs
it is the other term for antigen, other term for antibody
agglutinogen, agglutinin
are named for the antigens present or absent on the surface of the red blood cells
Blood groups
_________ of antigens depends on an individual’s ______.
Presence or absence, DNA
express different types of enzymes.
DNA
known as transferases, catalyze a series of
reactions in which they transfer sugar units
Enzymes
an enzyme is known as?
Transferases
are responsible for the type of antigen expressed
on the RBCs
Enzymes
meaning it will hasten or speed up the reaction
Catalyze
meaning of NAGA?
N-Acetylgalactosamine
It has about 2 million blood group antigens on its cell
membrane
Single RBC
what do all blood type individuals express that is found on the red blood cell?
Express a precursor oligosaccharide on the red blood cell
meaning of p.o
precursor oligosaccharide
all humans also express _________ that transfers and attaches fucose to the p.o.
transferase enzyme
what is produced after the binding of fucose to the p.o?
formation of the H-antigen
how is formation of the H-antigen formed?
by the binding of the p.o and fucose
__________ depends on the DNA of the individual then this DNA expresses diff. enzymes wherein their function is to transfer sugar units.
presence or absence of the antigen
a type of blood where it express a certain transferase enzyme which attaches an N-acetylgalactosamine to the H Antigen
Blood type A
what is the sugar unit of the Blood type A
Acetylgalactosamine
With the attachment of _________ the carbohydrate chain now becomes _______ . Hence, a blood type A
individual therefore has the _________.
Acetylgalactosamine, antigen A, A antigen
in formation of blood type A what is needed first? Where will it attached to? What will form after the attachment? After the creation of the H antigen, what will be needed again to create an A antigen?
presence of the precursor oligosaccharide, a focuse will be attached to it through a certain transferase enzymes. Forming the H antigen. H antigen will then N-acetylgalactosamine which forms the A antigen
An antigen is present in an individual the person that is considered Blood Type A.
A antigen
a type of Blood H antigen, which is made up of the precursor oligosaccharide and fucose. it is then attached to a sugar group called D-Galactose
Blood type B
what is the sugar unit of blood type A to the H antigen?
Acetygalactosamine
What is the sugar unit of blood type B to the H antigen?
D-Galactose
how is antigen B formed?
Precursor oligosaccharaide and fucose forms H antigen, H antigen will then bond with D- galactose due to a different enzyme. With the attachment of the D-galactose Antigen B is formed
a type of blood where Both enzymes that transfers N-acetylgalactosamine and the other that transfers galactose are expressed.
Blood type AB
the RBC of Blood type AB expresses?
Both A and B antigen
A type of blood where it only has H antigens on the RBC?
Blood type O
Blood type O, A, B, AB differences?
O has only H antigens and does not have N-acetylgalactosamine and galactose to the H Antigen
A has an A antigen, its H antigen has a sugar molecule of Acetylgalactosamine
B has a B Antigen, its H antigen has a sugar molecule of D-Galactose
Blood type AB both A and B antigens and its H antigen has a sugar molecule of N-Acetylegalactosamine and galactose
a type of blood where it Do not have enzyme that transfers n-acetylgalactosamine and galactose to the H antigen
Blood type O
a type of blood where neither A or B antigens are expressed by the RBCs in blood group O individuals.
Blood type O
what absence is seen in the blood type O?
Absence of both A and B antigen
what is Developed early in fetal life?
ABO Blood Group Antigen
What is Developed in the utero (uterus womb of the mother) at 5 to 6 weeks of gestation during pregnancy
ABO Blood Group Antigens
where is the ABO Blood group antigen being developed? at how many weeks?
Developed in the Utero (uterus womb of the mother) at 5-6 weeks gestational period
when are antigens detectable at this time of pregnanacy?
5-6 weeks of gestation during pregnancy
at what age is the expression of A and B antigens on the RBCs fully developed?
2-4 years of age
the formation of ABH antigens results from the interaction of genes at three separate loci which are?
ABO, H, Se
What does not code for the production of antigens?
gene
What do genes produce that add sugars to basic precursor substance?
specific glycosyltransferases
The sugars that are added to basic precursor substance rae referred as?
n-acetylgalactosamine, galactose
What is precursor oligosaccharide ?
is a paragloboside or glycan is the same basic precursor material from which A, B, and H antigens all originate
it is the precursor structure on which A and B antigens are made and acts as the acceptor molecule for the two sugars that make
the A and B antigens?
H antigen
The H antigen is a building block for which antigens
A and B
It is not part of the ABO system and their inheritance influences the expression of the A and B antigens?
H and Se genes
It must be inherited to form ABO antigens on the RBCs?
H gene
It must be inherited to form ABO antigens in secretions?
Se gene
Blood group O inherits at least how many H genes and O genes?
1- H gene
2- O gene
The H gene elicits the production of an enzyme called?
𝘢-2- Lfucosyltransferase
It transfers the sugar L-fucose to an
oligosaccharide chain?
𝘢-2- Lfucosyltransferase
It is the sugar responsible for H specificity?
L-fucose
What sugars are responsible for H, A, and B Antigen Specificities?
Glycosyltransferases and Immunodominant sugars
They are integral parts of the membranes of RBCs, endothelial cells, platelets, lymphocytes, epithelial cells?
ABH antigens
These are antigens that can also be found in all body secretions?
ABH-soluble antigens
It is present or found in the serum or plasma of the person and is formed when our immune system is exposed to non-selfantigens?
ABO Antibodies
______, similar to ABO blood type antigens, like antigen A AND antigen B, are found in nature.
Antigen
Antigens are Expressed by __________ such as those found in the human intestines and in many food stuffs.
common microorganisms
____________ of this individual express the A antigen on its cell membrane.
BLood type A
Since antigen A is already present and is recognized by the body as the ________, the similar A antigen on the microbial surface will also be recognized as ______.
self-antiagent, SELF
These microbes also have antigen B and remember that type A individuals _______ Antigen B so that makes the antigen B absent or missing on the _______.
do not express, red blood cell
This microbial antigen B will be recognized as ________.
non-self
What antibodies are produced by the
bacterial antigen B?
Anti-B antibodies
In an individual with a blood type A, anti B antibodies are found in their ______.
serum
Individuals normally produce antibodies directed against the A or B antigen ______ from their RBCs
absent
These antibodies are produced without any exposure to RBCs which is why they are described as?
naturally occurring
_______ production is initiated at birth, but titers are generally _______ for detection until infants are _____ months old
ABO production, too low, 3 to 6
Antibody production peaks at what ages in life?
5 and 10 years
Which people usually have lower levels of anti-A and anti-B?
Elderly people
ABO antibodies can cause ________ if the wrong ABO blood group is transfused, potentially resulting in patient death
rapid intravascular hemolysis
It must be double checked or even triple checked if it is the really the one intended for the patient or recipient.
Blood bag
What is the universal donor?
O blood type
What is the universal receiver?
AB blood type
Why do Blood Type AB only donate blood to Blood Type
AB?
Because of the antigens present on its cell.
Why do Blood Type AB is the universal recipient or
receiver?
Because they don’t have both anti A & B antibodies that can
react with the antigens present in the other blood types
Why do Blood Type O can donate to all blood types?
Because there no A or B antigens present on its cell
membrane
Blood Type O has both Anti-A and Anti-B antibodies. Wouldn’t the antibodies of blood type O cause a hemolytic transfusion reaction to the recipient since the other blood types have B-antigens?
How come?
It can still cause a reaction. However, it is just very
minor or weak and is referred to as clinically
insignificant.
Because of the type of antibodies of the ABO. They are IgM (Immunoglobulin M) anti-bodies and usually do not produce very severe reactions.
Blood type that is usually used for emergency purposes and in caes where patient’s blood type is still unknown?
O blood type
Why can AB receive blood from other blood types?
Because they don’t have both anti A & B antibodies that can
react with the antigens present in the other blood types
Why do Blood Type O can receive blood from Type O
only?
Because it has both Anti-A and Anti-B which can also react
with the antigens in the other blood type.
What is the immunodominant sugar present in blood
type A individuals?
N-acetylgalactosamine
What is the immunodominant sugar present in blood
type O individuals?
None. They only have H antigen and do not have
additional sugars attached.
What is the basic precursor material or the
oligosaccharide from which A, B, and H antigens
originate?
Paragloboside or Glycan
How are antibodies formed?
Formed when the immune system is exposed to nonself-antigens
What antibodies are present in blood type O individuals?
Anti-A & Anti-B
Blood type AB can only receive blood from what blood
types?
Blood Types A, B, AB, and O
It is done to determine the blood type of a person, which is a very critical step in the process of blood transfusion?
Routine ABO Testing
It is the most frequently performed test
in blood bank?
ABO blood grouping
a transfusion of an incompatible blood can cause
_________ reactions or can even be fatal.
hemolytic transfusion
It must be performed on all donors and recipients?
ABO forward and reverse typing tests
The first individual to perform both methods, forward and reverse typing?
Karl Landsteiner
What are the two methods did Karl Landsteiner used ABO Blood typing?
Forward Typing, Reverse Typing
It is detecting the antigens and in order to detect the antigens, we
have to use known anti-A, anti-B antisera
Forward Typing
Forward Typing is also known as?
Cell Grouping
Uses known sources of commercial antisera (anti-A, anti-B) to
_______ on an individual’s RBCs
detect antigens
Forward typing can be done on a ________ at room temperature
slide or in a test tube
what does IgG stand for?
Immunoglobulin G
what Type of Antibodies that can produce transfusion reactions?
IgG (Immunoglobulin G) Antibodies found in other blood
group systems
Usually, if RBC components are only being transfused, the antibodies will not be included anymore because they are found in the ___________. If RBC component only, there are ___________ present.
serum/plasma, no antigens
a type of blood that is usually used for emergency purposes like in the event that the patient really needs to be transfused with blood.
blood type O
what do you do when patient’s blood type is not yet known and there is not enough time for testing of the blood type? why?
done Blood type O, because type O does not have the A or B antigen
they Do not actually code for the production of antigens.
genes
they are Not responsible for producing the antigen itself.
genes
what do genes produce?
produces specific glycosyltransferases
whats the purpose of glycosyltransferases. What are the sugars referred to as?
they add sugars to basic precursor substance. they are referred are”
n-acetylgalactosamine
galactose
is a paragloboside or glycan
is the same basic precursor material from which A, B, and H antigens all originate
Precursor oligosaccharide
the precursor oligosaccharide is also known as?
paragloboside or glycan
_____________ is responsible for attaching sugars to the paragloboside or glycan
Specific enzyme transferases elicited
they are produced by an inherited gene
Specific enzyme transferases elicited
the precursor structure on which A and B antigens are made
H antigen
acts as the acceptor molecule for the two sugars that make the A and B antigens
H Antigen
the building block for both A and B antigen
H antigen
what has to be formed first so that specific sugar can be attached to it?
H antigen
A and B antigens can’t be formed without the presence of ___________.
H antigens
not part of the ABO system
H and Se (Secretory) genes
their inheritance influences the expression of the A and B
antigens
H and Se (secretory) genes
must be inherited to form ABO antigens on the RBCs
H gene
must be inherited to form ABO antigens in secretions
Se Gene
how is specifity of A and B antigen defined as?
immunodominant sugar present.
in Blood type A, what Immunodominat sugars are present?
H-antigen + N acetylgalactosamine
in Blood type B, what Immunodominat sugars are present?
H antigen + D-galactose
in Blood type AB, what Immunodominat sugars are present?
H antigen +
N acetylgalactosamine + D-galactose
in Blood type O, what Immunodominat sugars are present?
H antigen only
it has the highest concentration of the H antigen? What type of Blood?
Blood type O
blood group O inherit atleast how many H and O genes?
1 H gene and 2 O gene
elicits the production of an enzyme called 𝘢-2- L-fucosyltransferase that transfers the sugar L-fucose to an oligosaccharide chain
H-gene
what enzyme (Glycosyl-transferase) does the H gene produce?
an enzyme called a-2-L-fucosyltransferase.
purpose of 𝘢-2-L-fucosyltransferase
transfers the sugar L-fucose to an oligosaccharide chain
are responsible for H,A and B antigen specificities?
Glycosyltransferases and immunodominant sugars
are responsible for H,A and B antigen specificities?
Glycosyltransferases and immunodominant sugars
what are glycosyltransferases and immunodominant responsible for?
H, A and B antigen specificities
in the Antigen H, what is the gene? Glycosyl transferase? Immunodominant sugar?
H (FUT1), α-2-L- fucosyltransferase, L-fucose
in the A antigen what is its gene?Glycosyl transferase? Immunodominant sugar?
A, α-3-N-acetylgalacto saminyltransferase, N-acetyl-D-galactosamine
in the B antigen, what is its gene? Glycosyls transferase? Immunodominant sugar?
B, α-3-D-galactosyl transferase, D-galactose
ABH antigens are integral parts of the membranes of:
o RBCs
o endothelial cells o platelets
o lymphocytes
o epithelial cells
can also be found in all body secretions
ABH-soluble antigens
Present or found in the serum or plasma of the person
ABO Antibodies
Formed when our immune system is exposed to non-self-
antigens
ABO antibodies
Present against the antigen which is absent or missing on the
cell membrane of the RBCs
ABO ANTIBODIES
Detectable at
3-6 weeks months old
ABO Antibodies
what is fully developed by 2-4 years of age?
ABO Antigens
productions peaks at 5-10 years of age?
ABO Antibodies
at what age do antibodies by at peak?
5-10 years of age
they remain constant throughout life
ABO Antigens
Found on the membrane of the RBCs
ABO Antigens
They decline later in life
ABO Antibodies
They are found in the plasma/serumm
ABO Antibodies
What is the basic precursor material or the oligosaccharide from which A, B, and H antigens originate?
Paragloboside or Glycan
What is the immunodominant sugar present in blood type O individuals?
None. They only have H antigen and do not have
additional sugars attached.
How are antibodies formed?
Formed when the immune system is exposed to non- self-antigens
What antibodies are present in blood type O individuals?
Anti-A & Anti-B
Blood type AB can only receive blood from what blood types?
Blood Types A, B, AB, and O
A very critical step in blood transfusion because a transfusion of an incompatible blood can cause hemolytic transfusion reactions or can even be fatal.
ABO Blood groupings
what are tests that must be performed on all donors and recipients?
ABO Forward and Reverse typing
what is the relationship between the forward and reverse typing?
Inerse relationship
who was the first person to perform both forwards
Karl Landsteiner
what are the methods that karl landsteiner performed?
Forward and reverse typing
a typing test where it is the detecting of antigens
Forward typing
What are used in forward typing to detect antigens?
anti-A and anti-B antisera
forward typing is also known as?
Cell grouping
Uses known sources of commercial antisera (antiA,anti-B) to detect antigens on an individual’s RBCs ?
Forward typing
what are the commercial reagets bough in store for forward typing?
Blue angel and yellow bird
What reagent is used for anti-A and Anti-B for forward typing?
Anti-A Blue angel and Anti-B yellow bird
What is the procedure of forward typing?
1.Mixed on a slide with an applicator stick and then tilted back and forth & observed over a period of 2 minutes for agglutination
- Longer periods of incubation should be avoided because the effects of drying may be interpreted as agglutination/ clumping (pseudoagglutination). Or should be observed right away or over a period of two minutes only
A blood type where it contains antigens A and B; agglutinates with both sera after forward typing?
Type AB
What are being agglutinated on type AB after the forward typing results?
Antigens A and Antigens B agglutinates with both sera
What are being agglutinated on Type B after forward typing results?
Antigen B agglutinates with the Anti-B serum
What agglutinates type A after the forward typing results?
Antigen A agglutinates to the Anti-A serum
What agglutinates type O after the forward typing results?
none
Reverse typing is also known as?
Serum testing
a process Detecting ABO antibodies in the patient’s serum by using known reagent RBCs, namely A and B cells. What is this?
Reverse typing
what are unknown in reverse typing?
Antibodies
What are the reagents used in reverse typing?
A and B cells
how are antibodies detected in reverse typing?
By the reagents of A and B cells
what are tested in the patient’s serum for reverse typing?
Suspension of known group A and B cells
From the expected results of reverse typing, what is agglutinated in blood group B?
A cells
From the expected results of reverse typing, what is agglutinated in blood group A?
B cells
From the expected results of reverse typing, what is agglutinated in blood group O?
A and B
From the expected results of reverse typing, what is agglutinated in blood group AB?
none
How do you identify the results as forward or reverse typing?
Yellow and blue background for forward typing, while reverse typing results will only appear red, serum are colorless in reverse typing
Inheritance of ABO Blood Groups was first described in?
1924
What theory was first described in 1924?
Inheritance of ABO Blood Groups
it indicates an individual inherits one ABO gene from each parent and that these two genes determine which ABO antigens are present on the RBC membrane ?
Inheritance of ABO Blood group
The inheritance of ABO genes follows simple _______?
Mendelian genetics
ABO, like most other blood group systems is what type of expression?
codominant in expression
it is where 2 genes aren’t the same?
Heterozygous
It is where 2 genes are the same?
Homozygous
AO is it homozygous or heterozygous?
Heterozygous
AB is it homozygous or heterozygous?
Heterozygous
AA is it homozygous or heterozygous?
Homozygous
a type of dominance where dominant gene will be expressed ?
codominance
One position, or locus, on each _______ is occupied by an A, B, or O gene ?
Chromosome 9
What chromosome is occupied by an A, B or O Gene?
Chromosome 9
The O gene is considered an _______?
Amorph
a terms where no detectable antigen is produced in response to the inheritance of this gene since there is no O antigen.
Amorph
The group O phenotype is an _____________ trait with the inheritance of two nonfunctional O genes?
Autosomal recessive
it is an individual’s actual genetic make-up ?
Genotype
it is the outward expression of genes?
Phenotypes
Phenotypes are composed of what type of antigens?
Serologically demonstrable antigens
in the blood group mythology what personality traits are associated with blood group A?
Hangover
In the blood group mythology what personality traits are associated with blood group B?
Criminality
In the blood group mythology what personality traits are associated with blood group O?
Good teeth
Occur when unexpected reactions are obtained in the forward and/or reverse typing ?
ABO Discrepancies
Can be due to problems with the patient’s RBCs or patient’s serum, or problems with both the serum and cells?
ABO Discrepancies
what are the problems associated in the ABO Discrepancies?
Due to problems on patient’s RBCs or patient’s serum or problems with both serum and cells
All __________ must be resolved prior to reporting a patient or donor ABO blood group?
ABO discrepancies
Why should ABO Discrepancies must be resolved prior to reporting a patient or donor ABO Blood group?
In order to prevent hemolytic transfusion reactions
What are the cases of newborns with weakly reacting or missing antibodies?
ABO Antibody production is not detectable until 3-6 months of age
What test should you do to determine the newborn’s ABO Antibody?
Forward typing because antigens are detectable at 5-6 weeks of gestation while baby is still inside the mother’s womb
What are the cases of elderly patients with weakly reacting or missing antibodies?
Production of ABO Antibodies is depressed, since ABO antibodies decline later in life.
What can also cause ABO Discrepancies?
Technical errors some examples are
▪ incorrect or inadequate identification of blood specimens,
test tubes, or slides
▪ blood sample and test tube labeling errors
▪ failure to add reagents or failure to add sample
▪ contaminated reagents
▪ addition of incorrect reagents or sample
▪ clerical errors or incorrect recording of results
▪ failure to follow manufacturer’s instructions
What should you do to resolve the resolution of errors of blood?
- Serum and antiserum should always be added first , followed by the patients or reagent RBCs to avoid:
o reagent contamination
o potential omission of either patient sample or reagent
o So that you will not forget to add the sample especially that the serum is colorless, so if you add the known red cells first you might forget or get confused if you were able to add the patient’s serum or not - Results must be recorded immediately after obtaining them to avoid transcription errors.
- Always examine reagent vials concurrently while performing ABO testing and quality control testing for possible contamination
- Make sure any and all technical factors that may have given rise to the ABO discrepancy are reviewed and corrected
5.Obtain adequate information regarding the patient’s age, diagnosis, transfusion history, medications, and history of pregnancy
- If the discrepancy persists and appears to be due to an error in specimen collection or identification, a new sample must be drawn from the patient and all RBC and serum testing must be repeated. - So, when a discrepancy is encountered all results must be recorded, but the interpretation of the ABO Blood Type must be delayed until the discrepancy is resolved.
ABH antigens are integral parts of the membranes of:
RBCs
Endothelial cells
Platelets
Lymphocytes
Epithelial cells
why is the result of serum ABO testing before 3-6 months of age cannot be considered as valdid?
because some or all of the antibodies present maybe maternal antibodies or antibodies of the mother that has crossed the placenta and not from the baby himself/herself.
