Major Blood Group (ABO) 8.4

A substance that is capable of eliciting an immune response when introduced in-vivo.

Antigen

Protein substance secreted by plasma cells in response to, and interacting specifically with an antigen.

Antibody

Ability of anitgens to stimulate an immune resonse.

Antigenicity

Biological unit of heredity, located at a definite position on a particular chromosome.

Gene

The specific location of a gene on a given chromosome.

locus/loci

the listing of gense actually found on a pair of chromosome.

genotype

the listing of antigens expressed.

phenotype

alternate form of a series of genes that occupy a single locus on either of a pair of chromosomes.

Allele

gene loci located so close together they are inherited together as a single unit.

linked gene

what is an example of a linked gene?

complement

two identical genes in a pair.

homozygous gene

Two unlike genese (alleles) in a gene pair.

heterozygous gene

if only one gene in a heterozygous gene pair is expressed, the expressed gene is considered to be this.

dominant

if one gene in a heterozygous pair is not expressed it is considered to be this.

recessive

if both genes in any pair express themselves, they are considered to be this.

codominant

In blood bank, an amorphic gene does not express itself on a red cell.

Amorphic gene

antibodies produced without exposeure to an antigen. (ISO-Antibodies)

naturally occurring

The ABO blood group was discovered in 1900 by ____________.

Karl Landsteiner

what are the four RBC classifications?

ABABO

what are most serious transfusion accidents caused by?

ABO incompatibility

A person who _____ A and/or B antigens, will have iso-antibodies in their serum against those antigens.

Lacks

ABO Iso-antibodies are capable of causing rapid and total __________ of incompatible blood intravascularly.

destruction

intravascular transfusion reactions generally reslut in ________.

death

compatibility of ABO groups between _________ and ___________ is the foundation on which all other pre-transfusion testing depends.

donorrecipient

What are the three major antigens of the ABO system?

ABH (O)

what are the four major antibodies of the ABO system?

Anti-AAnti-BAnti-A,BAnti-H

The backbone exists in _____ forms, two are predominantly seen.

four

what are the two predominant backbone forms?

Type I (Secretor, saliva)Type II (RBC)

A backbone molecule inserts into the RBC membrane and has what four terminal sugars?

D-galactoseN-acetylglucosamineD-GalactoseGlucose

What are the three genes that influence the human major blood groups?

H geneA geneB gene

what are the two alleles in the H system?

Hh

what antigen in the H system is the precursor on which group A and B are built.

H

the Hh locus is on which chromosome?

19

The H gene causes production of L-______-Transferase.

fucosyl

the enzyme L-fucosyl-transferase, in the H system, causes addition of __________ to the backbone.

L-Fucose

the h gene is a rare _______ which produces no enzyme.

amorph

what is the extremely rare genotype known as bombay?

hh

The ABO gene locus is on which chromosome?

9

what are the two codominant genes in the ABO system?

AB

what are the three alleles in the ABO system?

ABO

this is a rare Amorph gene int eh ABO system where H antigen remains unchanged.

O gene

lack of the A or B gene produces what blood type?

O

what is the immunodominant sugar responsible for H specificity?

fucose

the A gene causes production of the enzyme N-_____________-transferase.

acetylgalactosaminyl

the ABO precursor combined with the sugar ______ is known as the A antigen, blood type A.

GalNac

the B gene causes production of the enzyme ________ transferase.

Galactosyl

in the B gene, Galactosyl-transferase bonds what to the ABO precursor?

D-galactose (Gal)

The ABO precursor combined with the sugar ____ is known as the B antigen, blood type B.

Gal

Each person inherits ___ ABO gene from each parent?

one

A and B genes dominate what gene?

O

pehnotypes may or may not indicate the ___________.

genotype

group AB person has what genotype?

AB

Group A person may have what genotypes?

AAAO

group B person may have what genotypes?

BBBO

the major A subgroups represent what precent of all the subgroups?

99.9%

what is the most common A subgroup?

A1

which A subgroup converts almost all H precursor?

A1

A1 will react with _______ lectin.

Anti-A1

These are RBCs that are intermediate between A1 and A2.

Aint

Which A subgroup gives a weaker reaction with Anti-A1 lectin but a stronger reaction with Anit-H?

Aint

what is the second most common A subgroup?

A2

what percent of A2 persons will form naturally occuring Anti-A1?

1-8%

22-35% of A2B persons will from ________.

Anti-A1

what is the thrid most common A subgroup?

A3

this subgroup makes up approximately 1:1000 or less than 0.1% of group A and group AB people.

A3

this is a characteristic agglutination pattern of small agglutinates in sea of non-agglutinated free RBC.

Mixed field

which A subgroup shows mixed field during the phenotype of the antigen?

A3

All A subgroups are made from the type ___ backbone?

II

Subgroups differ in the amount of ___ antigen present on the RBC.

A

the A subgroups are confirmed using what reagents?

Anti-A1 lectinAnti-H lectin

Anti-A1 lectin is extracted from what seeds?

Dolichos Biflorus

Anti-H lectin is extracted from what plant?

ulex europaeus

what is the A2 RBC reagent?

donor blood

which A subgroup has the most amount of A antigen?

A1

which A subgroup has the least amount of A antigen?

A3

ABO iso-antibodies are most often ____ anitbody.

IgM

ISO antibodies are _______ agglutinins?

saline

Ison antibodies react well at room temperature but are best at what temp?

Refrigerator

this is the identification of the ABO antigen (RBC).

forward typing

This is the identification of the ABO antibody. (serum/Plasma)

Reverse typing

how many tubes are used when performing ABO forward and reverse typing?

six

what percent cell suspension should be used for ABO forward and reverse typing?

2-5%

what is the reagent to suspension ratio for forward typing?

1:1

what is the reagent to serum ratio for reverse typing?

1:2

forward and reverse typing should be read _________ for agglutination.

macroscopically

forward typing is the phenotype of the patient's __________.

antigen

Reverse typing is the phenotype of the patient's ________.

antibody

this is used in blood bank to increase the efficiency and productivity of donor and patient testing?

automation

Blood typing automation uses _______ phase technology.

solid

what are three examples of solid phase automations in the blood bank?

ABS2000ROSYS platoThe Galileo

this automated technique performs ABO/RH and AB screens/crossmatch using a gel card containing dextran acrylamide gel particles, and does not require washing.

the gel system

what are two examples of the gel system?

ortho provue (fully automated)tecan megaflex (semi automated)

Lukemia depressens _______ expression on the RBC.

antigen

what is an example of depressed antigen expression?

acquired B phenomenon

Carcinomas of the ______ or _______ can cause antigens to be undetectable.

stomachpancreas

what are three diseases that can cause acqured B phenomenon?

intestinal obstructionCarcinoma of colon or rectumSepticemia with E. coli or Proteus mirablis

various lymphoma's, malignant non-hodgkin's, very youg or elderly patients, or immunosuppressant therapy can cause a ________ production of ABO ISO-antibodies.

Decreased

true or falsediscrepancies between forward and reverse grouping are generally technical in nature.True False

true

what are three causes of tecnical error in discrepancies between forward and reverse typing?

recheck ID of specimenClerical errorsFailure to add reagent.

if not technical, ABO discrepancies fall into one of ______ major categories.

four

which group of ABO discrepancies involves antibodies.

group I

which group of ABO discrepancies involves antigen?

Group II

which group of ABO discrepancies involves protein?

group III

which group of ABO discrepancies involves miscellaneous?

group IV

what are three causes of group I discrepancies?

immunodeficiencyleukemia or lymphomachimerism

this is a rare condtion in which there are two cell population in an individual.

chimerism

true or falsechimerism is often artificial?

chimerism

normal ABO reactions are ___ or stronger?

3+

if reactions are 1+ or less: incubate for 15-30 minutes at _____ temp.

room

what are three causes of group II discrepancies?

minor subgroups of A or BHodgkin's diseaseAcquired B phenomenon

which group of discrepancies can be caused by group specific substances?

group II

in group III discrepancies, __________ formation can cause pseudo agglutination.

rouleaux

multiple myeloma and hodgkin's lymphomas can cause what group of discrepancies?

group III

_________ the patient's red cells several additional times with saline will remove most of the protein causing the rouleaux formation.

washing

the resolution of which group of descrpancies involves saline replacement techniques?

group III

what are five causes of group IV discrepancies?

polyagglutination (T antigen)Cold reactive antibodieswarm autoantibodiesunexpected ABO iso-antibodiesAntibodies against the antisera

for group IV discrepancies patients cells should be tested with what?

lectin

the resolution of what group of discrepancies may involve warming the blood to 37oC?

Group IV

this is the removing of antibody from surface of RBC.

elution

the resolution of which group of discrepancies may involve elution?

group IV

True or falseall ABO discrepancies must be resolved before blood is released to patient for transfusion.True False

true

all reagents for ABO typing should be stored at what temperature when not in use?

1-6oC