Kidd

Question 1

What is the structure of the Kidd antigen?

Answer 1

Integeral glycoprotein that passes membrane 10X
3rd loop carries ABO antigens
4th loop carries Jka/Jkb

Question 2

What is the JK3 allele?

Answer 2

JK3 is present when either Jka or Jkb is present

JK01N and JK02N are null genes that cause Jk(a-b-)

Question 3

What are the characteristics of Jk antigens?

Answer 3

Well developed at birth
Enhanced by enzymes
Resistant to DTT
Poor immunogens

Question 4

Can Jk antibodies activate complement?

Answer 4

Jka antibodies with an IgM component can activate complement. IgG can’t.

Question 5

What the characteristics of JK antibodies?

Answer 5

Primarily IgG1 and IgG3
1/2 examples will activate complement
Intravascular hemolysis can occur; usually extravascular
Shows dosage; often reacts only w/ double dose cells
Very labile in vitro and vivo
May be enhanced by using 4 drops of serum

Question 6

What is the prevalence of Jka and Jkb in Whites?

Answer 6

Both are about 75%

Question 7

What is the prevalence of Jka and Jkb in blacks?

Answer 7

91% of blacks are Jka+

43% of blacks are Jkb+

Question 8

Where are kidd antigens found in the body?

Answer 8

Kidd antigens are found on the kidney and Kidd antibodies have caused renal transplant rejection

Question 9

What is a way to screen for Jk(a-b-) blood?

Answer 9

Test red cells with 2 M urea
Jk(a-b-) will resist lysis because Jka and Jkb are Urea transports and will allow Urea to flood cell and cause osmotic imbalance

Question 10

What is the amorphic Jknull phenotype?

Answer 10

2 silent JK genes inherited
Lack Jka, Jkb, Jk3
Very rare but seen in Polynesians
Can make anti-Jka, Jkb, and Jk3

Question 11

What is the suppressor In(Jk) phenotyope?

Answer 11

In(Jk) is a dominate inhibitor gene
Found in Japanese 
Less common that amorph
Jka, Jkb, and Jk3 can be detected by adsorb/elution
Will not make anti-Jk3
Cell will not be lysed by 2 M Urea

Question 12

What is the function of Kidd protein?

Answer 12

It is Urea transporter. As RBC’s pass through the Kidney’s they uptake Urea to avoid shrinking and as the RBC’s leave the Kidney the Urea exits.
Antigens in the Kidney help concentrate urea

Question 13

What chromosome is Jk gene located on?

Answer 13

Chromosome 18

Question 14

What is the gene name?

Answer 14

SCL14A1
or
HUT11A (Human Urea Transporter)

Question 15

What is the molecualr difference between Jka and kb?

Answer 15

SNP results in Jka or Jkb

Null gene are a result of premature stop codon

Question 16

What population is JK*2N.01 found in?

Answer 16

JKb null gene found in Melanesians

Most common

Question 17

What population is Jk*2N.06 found in?

Answer 17

Jkb null gene found in Finns

2nd most common

Question 18

What is anti-Jk3?

Answer 18

made in immunized Jk(a-b-) people
Not associated with severe HDFN
NOT anti-Jka + anti-Jkb