Deck 4: Abo and H Blood Group Systems and Secretor Status

Question 1

To distinguish between an A₁ and A₂ blood type, which reagent is used?

A) Ulex europeaus lectin
B) Anti-A,B
C) Monoclonal anti-A
D) Dolichos biflorus lectin

Answer 1

D
A₁ lectin will agglutinate A₁ red cells, not A₂ red cells.

Question 2

Why is it sometimes necessary to distinguish A₁ and A₂ blood types?

A) To resolve a discrepancy between the forward and reverse typing
B) To prevent A₁ recipients from receiving A₂ blood
C) To determine the secretor status of group A individuals
D) To prevent hemolytic disease of the newborn

Answer 2

A
Routine testing with anti-A₁ lectin is necessary to resolve a discrepancy between the forward and reverse typing. Individuals who possess the A₂ antigen can make anti-A₁ antibody.

Question 3

A group A man marries a group AB woman. The father of the group A man was group O. What possible ABO phenotypes could be expected in the offspring?

A) Group A, B, AB, and O
B) Group A and B
C) Group A, B, and AB
D) Group A and AB

Answer 3

C
The group A man must be genotype AO because the O gene was inherited from his father. A Punnett square with a group AB yields three potential phenotypes for the children: A, B, and AB.

Question 4

Given the following ABO phenotyping data:
What could be a plausible explanation for this discrepancy?

A) T-activation of red cells
B) Group O blood products given to group A
C) Rouleaux formation
D) Positive direct antiglobulin test

Question 5

What substances are found in the saliva of a group A person who also inherited the secretor gene?

A) A, H
B) H
C) A, Se
D) A, B, H

Question 6

The test procedure that combines patient's serum with commercial A₁ and B reagent red cells is called:

A) ABO forward grouping.
B) ABO reverse grouping.
C) antibody screen.
D) antibody panel.

Question 7

Approximately what is the percentage of individuals who demonstrate H in their saliva?

A) 15%
B) 50%
C) 80%
D) 98%

Question 8

According to Landsteiner's rule, what ABO antibody will be detected in a group A individual's serum?

A) Anti-A
B) Anti-B
C) Anti-A,B
D) None

Question 9

A blood sample from a 90-year-old man was submitted to the blood bank for a type and screen before surgery. The forward type demonstrates as a group A, whereas the reverse type appears to be group AB. The most likely cause of the discrepancy is:

A) contaminated reagent antisera.
B) rouleaux formation.
C) that the patient has autoantibodies.
D) that patient has low-titer isoagglutinins.

Question 10

What ABO phenotype would agglutinate in the presence of anti-A,B produced by group O individuals?

A) A only
B) B only
C) A and B
D) O only

Question 11

The subgroup of A with the least amount of A antigen is:

A) A₃.
B) A_x.
C) A₂.
D) A_el.

Question 12

What forward typing reagent can be used to confirm group O units before placing them in inventory?

A) Anti-A
B) Anti-B
C) Anti-A,B
D) Anti-H

Question 13

Which of the following situations is most likely to cause intravascular hemolysis when an incompatible transfusion is given?

A) Group B packed cells to a group O recipient
B) Group A packed red cells to a group AB recipient
C) Group AB plasma to a group A recipient
D) Group AB plasma to a group O recipient

Question 14

A recipient with group A phenotype requires a transfusion of 2 units of frozen plasma. Which of the following types are appropriate to select for transfusion?

A) AB and B
B) B and A
C) O and A
D) AB and A

Question 15

What would be the agglutination reaction of red cells from a Bombay phenotype with anti-H lectin?

A) Strong 4+
B) Mixed field
C) Weak 1+
D) Negative

Question 16

Which ABO phenotype selection contains the most H antigen and the least H antigen, respectively, on the red cell's surface?

A) O, A₁B
B) A₂, A₁B
C) B, A
D) A₁B, O

Question 17

Select the appropriate strategy if the results of red cell and serum testing in the ABO typing procedure have negative agglutination reactions.

A) Wash patient cells with warm saline.
B) Use polyclonal typing reagents.
C) Perform an autocontrol.
D) Incubate tubes at room temperature or 4° C with an autocontrol.

Question 18

What percentage of the group A population are type A₂?

A) 1%
B) 10%
C) 20%
D) 35%

Question 19

A patient's red cells are agglutinated by anti-B, but not by anti-A. This person would have which of the following ABO phenotypes?

A) Group B
B) Group O
C) Group AB
D) Group A

Question 20

Most "naturally occurring" ABO system antibodies fall into which class?

A) IgA
B) IgM
C) IgE
D) IgG

Question 21

Match the immunodominant sugar that corresponds to the ABO system group or antigen.
a.D-galactose
b.L-fucose
c.N-acetylgalactosamine
d.None of the above
Bombay

Question 22

Match the immunodominant sugar that corresponds to the ABO system group or antigen.
a.D-galactose
b.L-fucose
c.N-acetylgalactosamine
d.None of the above
Group B

Question 23

Match the immunodominant sugar that corresponds to the ABO system group or antigen.
a.D-galactose
b.L-fucose
c.N-acetylgalactosamine
d.None of the above
H antigen

Question 24

Match the immunodominant sugar that corresponds to the ABO system group or antigen.
a.D-galactose
b.L-fucose
c.N-acetylgalactosamine
d.None of the above
Group O

Question 25

Match the immunodominant sugar that corresponds to the ABO system group or antigen.
a.D-galactose
b.L-fucose
c.N-acetylgalactosamine
d.None of the above
Group A