3. Blood groups I Flashcards
ABO common precursor molecule
H
type 1H
soluble antigens present in secretions and plasma
type 2H
antigens present on RBCs
H antigen structure includes an ——– added onto the terminal galactose
L-fucose
O transferase
Fucosyltransferase
A transferase
Acetylgalactosaminyltransferase
B transferase
Galactosyltransferase
A sugar
N-acetylgalactosamine
B sugar
D-galactose
Expression of ABO alleles depends on the —- gene
H
naturally-occurring IgG, reacts with both type A and type B cells
anti-A,B
found in type O people
clinical significance of anti-A,B
able to cross placenta and cause mild HDFN
Tests for ABH secretions may establish true group when…
RBC antigens are poorly developed/absent
+ reaction with subgroup A1 cells
Dolichos biflorus
used to subgroup ABOs based on amount of H present
Ulex europaeus (H lectin)
most H –> least H among subgroups
O → A2 → B → A2B → A1 → A1B
hh
Bombay
antibodies present in plasma of Bombays
anti-A, anti-B, anti-A,B, and anti-H
homozygous hh inherited
classical Bombay
hh, Se
Para-Bombay
Lewis discovery
Mourant in 1946
Le gives fucosyltransferase which adds an L-fucose onto…
N-acetylglucosamine
Le are expressed on ———– adsorbed onto RBCs
glycosphingolipids
newborn Le phenotype
Le(a=b=)
Le + Se phenotype < 6yo
Le(a+b+)