Kidd Flashcards
1951
The first Kidd antigen,____, was discovered in a woman named____, who had a child with hemolytic transfusion reaction (HTR).
The antibody_____ was found in her serum.
Jka
Mrs. Kidd
anti-Jka
1953
Two years later, the second Kidd antigen,___, was discovered.
Jkb
1950-Present
Kidd antibodies were later found to be difficult to detect and a major cause of…
delayed hemolytic transfusion reactions (DHTRs).
The Kidd gene (Jk) is located on chromosome____
18
Kidd
KIDD GENE
●______&_____ (codominant alleles)
●____ (null/silent gene)
Jka and Jkb
Jk
GENOTYPE
JkaJka
JkaJkb
JkaJkb
Jk
Phenotype???
Jk (a+b-)
Jk (a+b+)
Jk (a-b+)
Jk (a-b-)
PHENOTYPES
Jk (a+b-)
Jk (a+b+)
Jk (a-b+)
Jk (a-b-)
Genotypes???
JkaJka
JkaJkb
JkaJkb
Jk
Common in blacks
JkaJka
Jk (a+b-)
Common in whites
JkaJkb Jk (a+b+)
JkbJkb Jk (a-b+)
T or F
• Well developed at birth (can cause mild HDN).
True
T or F
• Not very immunogenic, meaning they do not readily stimulate the immune system to produce antibodies.
True
• _____is detected at 11 weeks of gestation, while____ is detected at 7 weeks of gestation.
• Rarely causes_____, unlike Kell and Rh, which can cause severe anemia, hyperbilirubinemia, and stillbirth.
Jka
Jkb
severe HDN
Explain
KIDD ANTIGENS
● Common RBC antigens with the ability to show dosage
• If a person is homozygous (JkaJka or JkbJkb), they have more antigen and show a stronger reaction with antibodies.
• If a person is heterozygous (JkaJkb), they have a mixed population of antigens, leading to a weaker reaction.
Anti-Jka
Jk(a+b-)
Zygosity and reaction???
Homozygous (JkaJka)
3+ (Strong Reaction)
Anti-Jka
Jk(a+b+)
Zygosity and reaction???
Heterozygous (JkaJkb)
1+ (Weaker Reaction)
• Kidd glycoproteins are embedded in the_____ and are not very accessible.
• Enzyme treatment (e.g.,_____) enhances Kidd antigen detection by removing interfering proteins and making Kidd antigens more exposed.
• This makes Kidd antibodies more detectable in laboratory testing.
RBC membrane
papain, ficin, trypsin, bromelin
• The same applies to Kell antigens, which are only on RBCs but also found in the____.
testes
Anti-Jka and Anti-Jkb
• Both are_____ → Capable of crossing the____.
• Clinically significant → Can cause_____ and mild_____
• React at_____
IgG; placenta
delayed hemolytic transfusion reactions (DHTRs) and mild HDN
body temperature (37°C)
Anti-Jka and Anti-Jkb
• _____ is more frequently encountered than_____, but both are relatively uncommon.
Anti-Jka
Anti-Jkb
Kidd antibodies
Require potentiators for detection
(2) are needed to enhance detection.
Low Ionic Strength Solution (LISS) and Polyethylene Glycol (PEG)
Kidd antibodies
Disappear quickly from circulation
The titer of Kidd antibodies declines rapidly in vivo, making them undetectable in as little as two weeks
Not reactive to______
Some Kidd antibodies do not react with _____ the antihuman globulin (AHG) test, making detection more challenging
anti-IgG AHG
Kidd antibodies
Binds complement
Kidd antibodies can activate complement, leading to ____of red cells.
extravascular hemolysis
is a unique antibody in the Kidd system that reacts against both Jka and Jkb antigens.
Anti-JK3
Anti Jk3
It is associated with a rare phenotype
Jk(a-b-), which lacks both Jka and Jkb antigens
• Reacts against all red cells containing Jka and/or Jkb antigens → This means it will react with all Kidd-positive cells but will not react with Jk(a-b-) cells.
Anti-JK3
Anti-JK3
____type → Can cross the placenta and cause hemolysis in the fetus (HDN) and hemolysis after transfusion (HTR).
IgG
Anti-JK3
○ Commonly found in some individuals who are_____phenotype
Jk(a-b-) (null phenotype)
○ Common to Far East and Pacific Islanders
Anti-JK3
is a severe Kidd antibody found in Jk(a-b-) individuals and requires rare blood donors for transfusion
Anti-JK3
