BB 3: ABO Blood Group Review

what refers to the concept that individuals will form immune antibodies (naturally occurring) to ABO blood group antigens that they do not possess?

landsteiner’s law

the rule of thumb for determining an individual’s genotype is to always use the ____ genotype when trying to determine all possible genotypes.

heterozygous

which gene antigen is necessary for the expression of normal ABO antigens?

H

which gene antigen codes for the enzyme that adds the sugar, fructose, to the terminal sugar of a precursor substance?

H

the terminal sugar N-acetylglucosamine attaches to the ____ antigen.

A

the terminal sugar D-galactose attaches to the ____ antigen.

B

list the following ABO types from the greatest amount of H to the least amount of H:

• A1

• A1B

• A2

• A2B

• B

• O

O > A2 > B > A2B > A1 > A1B

what ABO gene antigen is associated with the following glucosyltransferase (enzyme): L-fucosyl transferase)?

H

what ABO gene antigen is associated with the following glucosyltransferase (enzyme): N-acetylgalactosaminyl transferase?

A

what ABO gene antigen is associated with the following glucosyltransferase (enzyme): D-galactosyl transferase?

B

what ABO gene antigen is associated with the immunodominant sugar L-fucose?

H

what is the secretory gene?

FUT2

which gene is described below

• inherited autosomal dominant

• responsible for expression of H antigen on glycoprotein structures in body secretions

• found in 80% of population

Se

what percent of the population are nonsecretors (sese)?

20%

“se” and “O” genes are examples of ____ genes, meaning nothing is expressed.

amorphic

which ABO linkage is founds for body fluids and secretions (aka Type 1)?

beta 1-3

which ABO linkage is founds for RBCs and some body fluids and secretions (aka Type 2)?

beta 1-4

RBC antigens or soluble substances: basic backbone are glycolipids?

RBC antigens

RBC antigens or soluble substances: basic backbone are glycoproteins?

soluble substances

RBC antigens or soluble substances: 1st sugar is GL?

RBC antigens

RBC antigens or soluble substances: 1st sugar is GALNAC?

soluble substances

RBC antigens or soluble substances: beta 1-4 linkage?

RBC antigens

RBC antigens or soluble substances: beta 1-3 linkage?

soluble substances

RBC antigens or soluble substances: FUT 1 by H gene for 2-L-fucosyltransferase?

RBC antigens

RBC antigens or soluble substances: FUT 2 by Se gene for 2-L-fucosyltransferase?

soluble substances

it is possible for a an AB and O parent to produce an AB child if the A and B antigens are inherited in the ____ position on the chromosome.

cis

ABO antibodies are naturally occurring and first appear after ____ months of age.

3-6

reverse typing on cord blood is not performed until 6 months or older. true or false?

true

group A and B antibodies are ____.

IgM

anti-A and anti-B (for group O) are primarily ____.

IgM

anti-A,B (for group O) is a single ____ antibody that cannot be separated into individual parts.

IgG

the ____ antibody in O individuals have the potential to cause HDFN in A (more commonly) or B babies because it is IgG and can cross the placenta.

anti-A,B

the H1 and H2 forms of the H antigen are ____ chains.

unbranched straight

the H3 and H4 forms of the H antigen are ____ chains.

complex branched

straight chain H1 is converted to ____ antigens.

A^a

straight chain H2 is converted to ____ antigens.

A^b

both A1 and A2 enzymes can convert the straight chain H antigens, but the ____ enzyme is less efficient.

A2

complex H3 is converted to ____ antigens.

A^c

complex H4 is converted to ____ antigens.

A^d

conversion of complex H antigens are done okay by the A1 enzymes but very poorly by ____.

A2

due to poor conversion, more unconverted H antigens are available on _____ RBCs.

A2

which A subgroup is described below

• unexpected anti-A1

• found in 1-8% of population

A2

which A subgroup is described below

• demonstrates a mixed field pattern of agglutination by anti-A and anti-A,B reagents

A3

which A subgroup is described below

• not agglutinated by anti-A reagent

• agglutinated by anti-A,B reagent

• anti-A1 commonly found

A_x

which A subgroup is described below

• cells demonstrate only about 10% or less agglutinated in mixed field agglutination with antisera

A_end

which A subgroup is described below

• not agglutinated or by anti-A or anti-A,B reagents

A_m

which A subgroup is described below

• unagglutinated by anti-A or anti-A,B reagents

A_y

which A subgroup is described below

• unagglutinated by anti-A or anti-A,B reagents

• adsorption and elution studies show the presence of A antigen

• unexpected anti-A1 present

A_el

which B subgroup may demonstrate a mixed field agglutination?

B₃

what refers to the absence of H, A, and B antigens on RBCs due to the mutation of the FUT-1 (H) gene producing a silenced gene incapable of coding for the H transferase?

bombay

____ patients will present with no agglutination with anti-A, anti-B, or H lectin.

bombay

the following describes a ____ patient:

• phenotypes O but is incompatible with group O RBCs

• potent anti-H in serum

  • presence of anti-A, anti-B, and anti-A,B

bombay

the following describes a ____ patient:

• A, B, H nonsecretor (no substances in saliva; silent FUT-2 [Se] gene)

• absence of H enzyme (a-2-L-fucosyltransferase) in serum and H antigen on RBC

• presence of A or B enzymes in serum

bombay

a true bombay recipient always needs another bombay donor or autologous units. true or false?

true

what condition is described below

• acquired, transient serological discrepancy

• usually found in type A patients who have septicemia, GI disorders, carcinoma of the colon/rectum, or wound infections

acquired B

what condition is caused by enzymes produced by certain strains of E. coli or some strains of Proteus vulgaris?

acquired B

in _____, enzymes can cause deacetylation of N-acetyl-galactosamine which leads to D-galactosamine (similar to D-galactose)

acquired B

the following ABO discrepancies indicates problems with ____

• weak reacting antigen (subgroups)

• missing antigens (null, deleted/mosaic)

• extra antigens

• mixed field (mf) reactions/chimerism

RBCs

the following ABO discrepancies indicates problems with ____

• weak reacting

• missing antibodies

• extra antibodies

serum

rouleux may cause false ____ reactions.

positive

the following are examples may result in extra ____ reactions in forward grouping:

• acquired B

• B(A) phenotype due to disease

• rouleux

• polyagglutination

• wharton’s jelly

antigen

for patients with acquired B, in order to resolve the discrepancy in testing, the patient’s RBCs should be tested with anti-B reagent acidified to the pH of ____.

6.0

group A people with acquired B should received group A ____ (or group O).

washed RBCs

only ____ typing is performed on cord blood.

forward

which example presents a newborn patient?

1

which example presents a geriatric patient?

2

which example presents a patient with hypogammaglobuinemia?

3

the following are examples may result in extra ____ reactions in reverse grouping:

• cold antibodies (allo- or auto-)

  • may include anti-I, H, M, N, P, Le

• rouleux

• anti-A1 in an A2 or A2B individual

• recent transfusion of incompatible plasma products

• IV Ig infusion

antibody

which example depicts anti-A1 in A2 or A2B patient?

1; 2

which example depicts irregular IgM allo antibodies?

3

which example depicts rouleux?

1; 3

which example depicts auto anti-I?

1; 3

____ can result in the following reactions

• stronger at IS

• weak at 37°C

• no agglutination at AHG

rouleux

the following may cause ____ in a sample:

• complement binding antibodies

• bacterial contamination

• physical causes

  • water (IV)

  • mechanical strain during blood collection

  • extreme temperature exposure (hot/cold)

hemolysis