Kell

Question 1

Kell system antigens:

Answer 1

36 antigens

7 pairs/ 1 triplet

Question 2

Kell antigen location

Answer 2

CD238

Kell spans the membrane once with a large c-terminal domain outside the membrane

Linked by disulfide bond to Xk protein

Question 3

Absence of Xk

Answer 3

Reduced expression of Kell glycoprotein and weakened Kell antigen

Question 4

KEL gene location

Answer 4

Chromosome 7q33

Question 5

XK gene location

Answer 5

chromosome Xp21.1

Question 6

Kell phenotype prevalence

Whites

Answer 6

K-k+: 91%
K+k+: 8.8%
K+k-: 0.2%

Question 7

Kell phenotype prevalence

Blacks

Answer 7

K-k+: 98%
K+k+: 2%
K+k-: rare

Question 8

Kpa prevalence

Answer 8

2% in whites

Not present in black or Japanese

Question 9

Jsa prevalence

Answer 9

20% in African American

Rare in white peoples

Question 10

Kell antibodies

Answer 10

Primarily IgG

Don’t bind complement

Clinically significant

Question 11

Anti-Kell HDFN

Answer 11

Associated with lower degree of hemolysis and fetal anemia predominantly from suppression of erythropoeisis

Question 12

Ko phenotype

Answer 12

K null

Results from homozygosity for various KEL mutations

Make anti-Ku (KEL5) and anti-Km

Question 13

Kmod

Answer 13

Show weak expression of Kell antigens (often only detectable by adsorption/elution)

Strong Kx expression

Make an antibody similar to Anti-Ku that reacts with everything except other Kmod

Question 14

Kell weakened antigen expression

Answer 14

Kmod

absence of Gerbrich Ge2 and 3, Kpa in cis

Question 15

McLeod syndrome

Answer 15

X-linked

Associated with acanthocytosis

Late onset muscular and neurological defects

Question 16

McLeod with CGD will make which antibodies

Answer 16

Anti-Km

Anti-Kx

Question 17

McLeod w/o CGD make which antibodies

Answer 17

Anti-Km only

Question 18

Hematologic abnormalities with McLeod

Answer 18

Decreased RBC survival
Acanthacytosis
Reticulocytosis
Reduced serum haptoglobin 
Increased bilirubin 

Compensated anemia