ABO System

Question 1

What are ABO antigens characterized by?

Answer 1

Immunodominant SUGAR/CARBOHYDRATE on cell surface

Question 2

The ABO gene is located on what chromosome?

Answer 2

Chromosome 9

Question 3

What is the most common blood type?

Answer 3

Blood type O

Question 4

T or F: ABO-incompatible blood transfusions account for the most transfusion-related deaths.

Answer 4

TRUE

Question 5

What gene locus synthesizes the H antigen/substance in RBCs?

Answer 5

FUT1

Question 6

If a person lacks the H-antigen/substance, what blood type do they have?

Answer 6

Bombay

Question 7

What sugar/carb gets added to H antigen to create blood group A?

Answer 7

N-Acetylgalatosamine

Question 8

What sugar/carb gets added to H antigen to create blood group B?

Answer 8

Galactose

Question 9

What genotype is Bombay?

Answer 9

Genotype: hh

Question 10

What would a Bombay individual type as?

Answer 10

Type O (Oh)

Question 11

What two substances would agglutinate subgroup A1?

Answer 11

Dilichos biflorus and Anti-A1

Question 12

Would you see agglutination for

Question 13

What subgroup(s) of cells would be agglutinated by Anti-A1?

Answer 13

A1 cells only

A2 and A2 subgroups would be negative

Question 14

What genotype is needed in order for A or B sugars to attach itself to H?

Answer 14

HH or Hh

Bombay is hh

Question 15

What blood group has the greatest amount of H antigen?

Answer 15

Blood group O

Question 16

What is the order of blood groups with the MOST to LEAST H-antigen?

Answer 16

O > A2 > B > A1 > A1B

Question 17

What is the order of blood groups with the LEAST to MOST H-antigen?

Answer 17

A1B < A1 < B < A2 < O

How I remember it: Oh! A BABY, A BABY Ahh!

Question 18

What is the Anti-H lectin?

Answer 18

Ulex europaeus

Question 19

What blood type will Ulex europaeus agglutinate and why?

Answer 19

This is an anti-H lectin. Ulex europaeus will agglutinate blood group O because group O genotypes as HH or Hh.

It will NOT agglutinate A, B, AB, nor Bombay (hh).

Question 20

What is the Se (secretor) gene?

Answer 20

Allows expression of A, B, H, and Lewis (b) in body fluids

Question 21

What 4 antigens are expressed in bodily fluids of people who are secretors?

Answer 21

A, B, H, and Lewis (b)

Question 22

Individuals who have H and Le (but not Se) will have what antigens on their RBCs and in saliva?

Answer 22

RBcs would have H and Le(a)

Saliva would have Le(a) only –> Le(a) still present in saliva even without secretor (Se) gene.

Question 23

Individuals who have H and Le, and Se will have what antigens on their RBCs and in saliva?

Answer 23

RBCs would have H, Le(b)

Saliva would have H, Le(b), and decreased amounts of Le(a) in bodily fluids