Blood Bank Solo 2 Study Questions

The mating of parents of which two ABO phenotypes can potentially produce offspring with ALL of the common four blood types

Types A and B

Which of the following is TRUE of anti-A,B but NOT of anti-A and anti-B?

Anti-A,B is predominantly IgG

Match each immunodominant sugar with its corresponding ABO antigen specificity

L-fucose: H

N-acetylgalactosamine: A

D-galactose: B

Briefly describe the differences between the H and Se genes

The H gene codes for the formation of alpha-2 fucosyltransferase, which adds a fucose to type 2 chains, forming the H antigen on red cells. The H antigen is required for the formation of all other ABO antigens

The Se gene codes for production of alpha-2-fucosyltransferase that modifies type 1 precursor chains, forming the H antigen on these precursor chains in secretions. Inheritance of the Se gene and ABO genes influence the presence of ABH antigens in body secretions

Which ABO group expresses the highest amount of H antigen

O

Which ABH antigens are found on the red cells of an individual with the genotype Hh, BO, sese

B and H

Which ABH antigens are found in the secretions of an individual with the genotype Hh, AB, sese

None

(We are asked about the ABH antigens in SECRETIONS. This individual did not inherit an Se gene. We would not expect to find any soluble ABH antigens in their secretions. Since an H gene was inherited, A, B, and H antigens would all be expected to be present on their red cells!)

The following reactions are obtained

Anti-A	Anti-B	A1 Cells	B Cells
4+	4+	0	0

What is the patient’s ABO type?

AB

The following reactions are obtained

Anti-A	Anti-B	A1 Cells	B Cells
4+	0	0	4+

What is the patient’s ABO type?

A

Consider the following results

Anti-A	Anti-B
0	4+

What ABO antibodies are expected in the plasma/serum of this individual?

Anti-A

Consider the following results

A1 cells	B cells
4+	4+

What antigens can be expected to be present on this patient’s red cells

None

(We are given the results for a reverse typing.

This patient appears to have anti-A and anti-B that are reacting with the reagent red cells, so we would expect this patient to forward type as group O. Since they have anti-A and anti-B, we would expect their red cells do not express either the A or B antigen.

The O antigen of course does not exist, but group O individuals express the unmodified H antigen, the precursor to the A and/or B antigens. The O gene does not code for a transferase to modify the H antigen (as the A and B genes do))

Consider the following confirm typing results on a group O donor red cell unit

Anti-A,B

0

What ABO group should the donor unit be labeled as based off these results?

O

Why is the reverse grouping not generally performed on neonates (under 4 months of age)

Antibodies are generally not present at birth

What ABO type(s) of donor red cells are compatible for a recipient with the following ABO testing results? Select all that apply

Anti-A	Anti-B	A1 cells	B cells
4+	0	0	4+

A, O

What ABO type(s) of donor plasma are compatible for a recipient with the following ABO testing results?

Anti-A	Anti-B	A1 Cells	B Cells
4+	4+	0	0

AB

What ABO type(s) of RBCs are compatible with a recipient who is group O?

O

Group O individuals are considered universal donors for the transfusion of RBCs and universal recipients for plasma transfusions. Provide an explanation for this statement

Group O individuals are considered to be universal donors for RBC transfusions because they do not have antigens that coat the outside of the red blood cells which allows this type to be transfused to all recipients because it won’t cause a transfusion reaction

Group O individuals are considered universal recipients for plasma because they already make anti-A and anti-B. So, any type of plasma (A, B, AB, or O) would be okay to give

Based on the following saliva study results, what does this patient’s ABO genotype appear to be?

	Anti-A + Saliva	Anti-B + Saliva
A1 cells	4+	NT
B cells	NT	0

NT = not tested

Either BB or BO

Which of the following statements is/ are TRUE regarding the A1 and A2 blood groups? Select all that apply

Ulex europaeus will give stronger reactions with A2 than with A1 RBCs

A2 RBCs have more H antigen than A1 RBCs

If an individual of the A2 subgroups has not produced anti-A1, it is easy to distinguish this subgroup from the A1 subgroup with routine testing

False

You suspect you have a patient with a subgroup of A

1) What additional test can be performed to prove their red cells are not A1 cells

2) What would be your suspected result?

Dolichos biflorus; negative

Match the lectin with the red cells they agglutinate

Dolichos biflorus: A1 or A1B cells

Ulex europaeus: O cells and variably with other ABO blood groups depending on the amount of H antigen available

Rank the following ABO types in order from HIGHEST amount of H antigen to LOWEST

1. Highest: O

2. A2

3. B

4. Lowest A1

Why can anti-H sometimes be found in an A1 or A1B individual

The specific immunodominant sugar blocks the presence of H antigen

Which of the following tests can be performed to classify ABO subgroups? Select all that apply

Secretor studies

Ulex europaeus reactivity

Adsorption-elution tests

Molecular testing

Anti-A,B reactivity

A patient with the A2 subgroup blood type has been identified by your facility. This patient has made an anti-A1. There are orders for 2 RBCs and 2 units of plasma to be set up for surgery

What type(s) of red cells and plasma may be selected for this patient? Defend your choices

They could receive O or A2 red cells because they have anti-B and anti-A1 in their plasma. Both of those would be safe. They could receive A or AB plasma. A plasma contains anti-B and AB plasma contains no ABO antibodies, so neither would react with the patient’s RBCs

Persons who inherit the h allele cannot form the H antigen because they do not produce which of the following?

L-fucosyltransferase

What ABO type does a person with Bombay phenotype appear to have?

O

Consider the following results

Anti-A	Anti-B	A1 cells	B cells	O cells	Auto control*
0	0	4+	4+	4+	0

*Auto control consists of testing a suspension of the patient’s red cells against the patient’s own serum/plasma

What additional test can be performed if a Bombay phenotype is suspected

Ulex europaeusNo

An individual has the genotype hh, AB, sese. Which antigens are found in the secretions?

None

An individual has the genotype hh, AB, sese. Which antigens are found on their red cells?

None

An individual has the genotype Hh, OO, sese. Which antigens are found in the secretions?

None

An individual has the genotype Hh, OO, sese. Which antigens are found on their red cells?

H only

Briefly differentiate between the Bombay and Para-Bombay phenotypes

Bombay: Arises when an individual inherits two h genes or two mutated H genes. Results in a silenced gene incapable of coding for the H transferase enzyme that acts on type 2 chains, thus no antigens are formed on red cells. Also associated with silenced Se gene, resulting in the absence of the H transferase enzyme that forms H antigens in secretions

Para Bombay: Described as H-deficient secretors. Characterized by either a mutated H gene with or without an active Se gene or a silenced H gene (hh genotype) with an active Se gene. H transferase enzyme activity is greatly reduced, and very small amounts of ABH antigens are formed.

Consider the following results

Anti-A	Anti-B	A1 cells	B cells
4+	0	0	0

Which result is most likely discrepant?

Negative reaction with B cells

A patient has the following ABO typing results

Anti-A	Anti-B	A1 Cells	B Cells
4+	4+	2+	0

What is the patients ABO type?

Unable to report without additional testing

RT, a 37 year old woman, is a first-time blood donor. She is a healthy donor with an unremarkable medical history and on no medications. Consider her ABO typing results

Anti-A	Anti-B	A1 Cells	B Cells
0	4+	3+	1+

Is the discrepancy associated with the red cell testing or the serum testing

Serum testing

Consider RT’s ABO typing results again (from the previous question):

RT, a 37 year old woman, is a first time blood donor. She is a healthy donor with an unremarkable medical history and on no medications

Anti-A	Anti-B	A1 Cells	B Cells
0	4+	3+	1+

What is a potential cause of this discrepancy? Select all that apply

B subgroup, Cold autoantibodies

Patient SPH requires a type and screen in preparation for correcting a bowel obstruction. His ABO Typing results are as follows

Anti-A	Anti-B	A1 Cells	B Cells
4+	w+	0	4+

Is the discrepancy with the patient’s red cells or the patient’s serum

Red cells

Consider SPH’s ABO typing results again (from the previous question):

Patient SPH requires a type and screen in preparation for correcting a bowel obstruction

Anti-A	Anti-B	A1 Cells	B Cells
4+	w+	0	4+

What is a potential cause of this discrepancy

Acquired B phenomenon

All of the following may result in unexpected antigen reactions except:

Hypogammaglobulinemia

Which ABO discrepancy is the BEST explanation for the following results?

Anti-A	Anti-B	A1 cells	B cells
4+	0	2+	4+

A subgroup

All of the following may result in rouleaux formation except

Leukemia

Given the following results, determine the MOST likely cause(s) of the following discrepancy

Anti-A	Anti-B	A1 cells	B cells
0	4+	0	0

Newborn sample

A recently transfused trauma patient has the following serological results

Anti-A	Anti-B	Anti-A,B	A1 cells	A2 cells	B cells
3+mf	0	3+mf	0	0	4+

Which is the MOST probably explanation for these results?

Group A patient transfused with O red cells

Which of the following situations has the potential to cause an ABO typing discrepancy with both the patient’s red cells AND the patient’s plasma? Select all that apply

Multiple Myeloma

Leukemia patient on Chemotherapy

Strong cold autoantibody

Which of the following is most consistent with the following serological discrepancy?

Anti-A	Anti-B	A1 cells	A2 cells	B cells
4+	2+	2+	2+	4+

Cold reacting autoantibody

Mixed field reactions can be associated with which of the following?

All of the above, aka

ABO subgroups, genetic chimeras, and transfusion

RB is a 30 year old woman who is admitted to the hospital the night before her scheduled C-section. She is in relatively good healthand has no significant medical history. A pre-op specimen is drawn and sent to the blood bank for testing. The following ABO typing results are obtained

Anti-A	Anti-B	A1 Cells	B Cells
4+	0	1+	4+

1) List 2 potential causes for this discrepancy

2) List 2 possible methods for resolving this discrepancy

From Travis:

The discrepancy here would appear to be the 1+ with the A1 cells. An ABO subgroup (A2 with anti-A1) is definitely a possibility here. For that you would want to test with your A1 lectin. Getting an out of ABO group transfusion is unlikely to cause extra reactions in the reverse. And since that is where the discrepancy is, washing the patients cell suspension wouldn't really help. That would only be useful if there were extra reactions in the forward type.

Consider the following results on a patient with a previous history of group O

Anti-A	Anti-B	A1 cells	B cells
0	0	0	0

1) List 2 possible scenarios that might cause this discrepancy

2) List 2 possible methods to resolve this discrepancy

Two possible scenarios that might cause this discrepancy are

1) Excess amounts of blood-group specific soluble (BGSS) substances present in the plasma, which sometimes occurs with certain diseases, such as carcinoma of the stomach and pancreas

2) Antibodies to low-prevalence antigens in reagent anti-A or anti-B can also cause weakly reactive or missing reactions in RBC grouping

Two possible methods to resolve this discrepancy are:

1. Using the 4+1 technique to add an additional 2 drops of plasma to the test tubes

2. Extend the incubation time at room temperature to 15-30 minutes

Consider the following ABO results from a patient admitted from the ER after a GSW

Anti-A	Anti-B	A1 Cells	B Cells
0	3+mf	3+	0

Which of the following is MOST likely true of the mixed field discrepancy?

History of transfusion of group O red cells

Consider the following results on a trauma patient

Anti-A	Anti-B	A1 cells	B cells
4+	4+	1+	0

If you are unable to resolve this discrepancy, what type(s) of red cells are acceptable to give this patient? Explain your reasoning

If unable to resolve the discrepancy with this patient’s sample, you would want to transfuse O red cells to this patient. This is because when blood is needed when the discrepancy cannot be resolved, you want to follow the TRO/TRAB process. So, although the patient is forwarding as an AB type, until the discrepancy is resolved you would want to transfuse O red cells to be safe

Which consideration should be made before beginning an ABO subgroup investigation?

ABH alteration caused by malignancy

Consider the following results

Anti-A	Anti-B	A1 cells	B cells
4+	0	3+	4+

The antibody screen is positive. An antibody panel is performed and an anti-M is identified. How can this ABO discrepancy be resolved?

Perform reverse typing with A1 cells negative for the M antigen

A patient has the following serologic testing

Anti-A	Anti-B	Anti-A,B	A1 cells	A2 cells	B cells
4+	2+	4+	2+	2+	4+

The BEST next step in the resolution of this discrepancy would be

Repeat typing after washing patient cells

The following results are obtained on a 34 year old man who is going into emergency surgery for a GI bleed

Anti-A	Anti-B	A1 cells	A2 cells	B cells
4+	0	1+	1+	4+

Which of the following is the next BEST step?

Repeat typing after performing a saline replacement

(From Travis: The extra weaker reaction with A1 cells could be an indicator that we have an A subgroup with an anti-A1. However, we also have a similar in strength reaction with our A2 cells- if we suspected an A2 individual with an anti-A1 we should observe a NEGATIVE reaction when testing their serum/plasma with A2 cells. This positive A2 reaction should point us in the direction of suspecting either spontaneous agglutination in the reverse (rouleaux) or a non-ABO antibody. 

Repeating the reverse typing with a saline replacement would resolve a reverse discrepancy due to rouleaux.)

Consider the following results on a 28 year old female

Anti-A	Anti-B	A1 cells	B cells
0	0	0	4+

What is the BEST next step?

Repeat all testing to rule out technical errors

Consider the following results on a 45 year old man

Anti-A	Anti-B	A1 cells	B cells	Auto control (patient plasma + patient cells)
4+	1+	1+	4+	1+

What will MOST likely resolve this discrepancy?

Incubating all tests at 37 degrees Celsius for 10 minutes

Consider the following results

Anti-A	Anti-B	A1 cells	A2 cells	B cells	O cells	Auto control (patient plasma + patient cells)
0	0	4+	4+	4+	4+	0

Which of the following is the BEST step?

Test patient cells against Ulex europeaus

Which of the following methods can resolve ABO discrepancies with extra antigen reactions? Select all that apply

Washing patient cells, Repeating testing with reagents from a different monoclonal source, and prewarming patient cells at 37 degrees Celsius for 10 minutes and then washing