Lewis Flashcards
Lewis gene name
FUT3
What transferase does the Lewis gene code for
L-fucosyl transferase
What needs to happen for Lea to be present
Lewis gene needs to add a fucosyl, then Lea will be positive on cells and secretions (even if Se is not present)
What needs to happen for Leb to be present
Se needs to add another fucosyl to precursor substance 1. Le+Se= Leb
Then Lea turns negative and Leb positive. Lea will still be present in secretions but not in RBC
Which Lewis phenotype has the stronges expression of ABO in secretions
Le a-b-
Which genes do parabombay have
No H but have Se and can also have Le
So ABO will be present in secretions but not on RBC. Le will be in secretions and RBC
Usual Lewis phenotype on secretors
Leb+
Lea positive frequency
Around 20%
Leb positive frequency
Around 60%
Which race is more Lea-b- more common in
Blacks (28%) whites are only 6%
What happens to Lewis antigens during pregnancy
Production is depressed and they elude off of the cells so mom will type as Lea-b- and can make antibodies
Are Lewis antigens developed at birth?
No, not well developed. Takes 10 days
Are Lewis antibodies IgM or IgG
IgM and can be naturally occurring
Lewis antigen effect on kidney transplant
People who express Lewis antigens have better allograft survival
How are Lewis antigens neutralized
Saliva
