Test 3: Other Blood Group Systems Flashcards
What are the naturally occurring carbohydrate blood group systems?
-ABO
-Lewis
-P
-I
(IgM)
What are the immune stimulated protein blood group systems?
-RH
-MNSs (IgM)
-Kell
-Duffy
-Kidd
-Lutheran
What causes unexpected antibodies in a patient?
the patient being “challenged” (exposure to antigens)
What is the most common Lewis phenotype?
Le (a-b+)
72% whites
55% blacks
What is the least common Lewis phenotype?
Le(a+b+)
rare for all populations
How do Lewis antigens get on RBCs?
they are passively absorbed
they are not of erythroid origin
Why do newborns type as Le(a-b-)?
not expressed on cord RBCs
What is diminished on maternal RBCs that will seroconvert after the birth of the baby? ***
Lewis antigens
-mothers will type as Le(a-b-) while pregnant
Where are Lewis antigens found?
all throughout the body: lymphocytes, platelets, tissues (organs),
saliva
Are Lewis antigens affected by enzymes?
no, resist enzymes
Lewis antigen _______ cause HRTs, _______ HDFN.
rarely, never
What are two reasons Lewis antigens never cause HDFN?
-IgM, cannot cross the placenta
-baby will not have antigens
Are Le(a) and Le(b) alleles?
No. (gene says yes or no)
What genes does the Lewis system depend on?
Hh, Se, and Le genes
-le, h, and se do not produce
products
If the Le gene is inherited, ____ substance is produced
Le(a)
What must all be inherited to convert Le(a) to Le(b)?
Le, H, and Se
Le(a+b+) RBCs are rare, except in what population?
Asian populations (10-40%)
Phenotype if Inherit only FUT3 (Lewis gene)?
Le(a+b-)
FUT 1 is ______ gene
FUT 2 is ______ gene
FUT 3 is ______ gene
H
secreter
Lewis
Phenotype if Inherit both FUT3 and FUT2
(Secretor gene)?
Le(a-b+)
True or False?
Lea does not turn into Leb
True
Why is anti-Le(a) not made with Le(a-b+)?
still produces small
amounts of Le(a)
What is significant about lele Se H genes being present, (Le a-b-)?
will make antibodies unless it is a baby
Le(a) —-> seen in secretions
If Lewis b, what do they still have in secretions?
Le a