Kidd Blood Group

Question 1

What are the 3 antigens in the Kidd system?

Answer 1

Jk(a), Jk(b), Jk3

Question 2

What is the function of the Kidd glycoproteins?

Answer 2

Urea transporter

Question 3

Are the Kidd antigens well developed on fetal red cells?

Answer 3

Yes

Question 4

What is the most common Kidd phenotype in the white population?

Answer 4

Jk(a+b+)

Question 5

What is the most common Kidd phenotype in the black population?

Answer 5

Jk(a+b-)

Question 6

In what population is the null phenotype Jk(a-b-) most commonly seen?

Answer 6

Polynesians

Question 7

Do Kidd antibodies show dosage?

Answer 7

Yes

Question 8

Do the Kidd antibodies bind complement?

Answer 8

Yes

Question 9

At what temperature do the Kidd antibodies react best?

Answer 9

37C

Question 10

Why are Kidd antibodies many times seen to cause transfusion reactions?

Answer 10

Their titers can quickly become undetectable. If a screen was not performed at the right time the antibody may not be detected until after a transfusion reaction due to incompatible blood (blood positive for the Kidd antigen).

Question 11

What alleles must an individual inherit to demonstrate a true Jk(a-b-) null phenotype?

Answer 11

2 silent Jk alleles

Question 12

What characteristic (other than the phenotype) can help identify Jk(a-b-) RBCs?

Answer 12

These RBCs will have delayed lysis in 2M urea

Question 13

What will happen to the Kidd antigens if an individual inherits the Dominant In(Jk) allele?

Answer 13

The Kidd antigens will only be expressed very weakly. The serologic testing usually will not even detect the Kidd antigens making the patient’s phenotype look to be Jk(a-b-)

Question 14

Can an individual who inherits the In(Jk) allele make an anti-Jk3?

Answer 14

No, because they still have very small amounts of Kidd antigens which means the Jk3 antigen is not foreign and antibody will not be created.