Kell Flashcards
Kell system antigens:
36 antigens
7 pairs/ 1 triplet
Kell antigen location
CD238
Kell spans the membrane once with a large c-terminal domain outside the membrane
Linked by disulfide bond to Xk protein
Absence of Xk
Reduced expression of Kell glycoprotein and weakened Kell antigen
KEL gene location
Chromosome 7q33
XK gene location
chromosome Xp21.1
Kell phenotype prevalence
Whites
K-k+: 91%
K+k+: 8.8%
K+k-: 0.2%
Kell phenotype prevalence
Blacks
K-k+: 98%
K+k+: 2%
K+k-: rare
Kpa prevalence
2% in whites
Not present in black or Japanese
Jsa prevalence
20% in African American
Rare in white peoples
Kell antibodies
Primarily IgG
Don’t bind complement
Clinically significant
Anti-Kell HDFN
Associated with lower degree of hemolysis and fetal anemia predominantly from suppression of erythropoeisis
Ko phenotype
K null
Results from homozygosity for various KEL mutations
Make anti-Ku (KEL5) and anti-Km
Kmod
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
Kell weakened antigen expression
Kmod
absence of Gerbrich Ge2 and 3, Kpa in cis
McLeod syndrome
X-linked
Associated with acanthocytosis
Late onset muscular and neurological defects