3. 3
Other blood group systems
A blood group system contains antigens controlled by a single gene (or by multiple
closely linked loci), and the system is genetically distinct.
There are 22 blood group systems, including the ABO, Rh, and Kell blood groups which
contain antigens that can provoke the most severe transfusion reactions
Example of other blood group systems:
i. Lewis (Le)
ii. P
iii. MNS
iv. Lutheran (LU)
v. Kell (KEL)
vi. Duffy (FY)
vii. Kidd (JK)
These blood groups are not routinely tested except in cases of difficult cross matches and
transfusion reactions, some of these may also lead to hemolytic disease of newborn.
3
4. 4
CONVENTIONAL NAME ISBT SYMBOL
BLOOD GROUP SYSTEMS
ABO ABO
MNSs MNS
P P1
Rh RH
Lutheran LU
Kell KEL
Lewis LE
Duffy FY
Kidd JK
Diego DI
Cartwright YT
Xg XG
Scianna SC
Dombrock DO
Colton CO
Landsteiner-Wiener LW
Chido/Rogers CH/RG
Hh H
Kx XK
Gerbich GE
Cromer CROMER
Knops KN
Indian IN
Ok OK
Raph RAPH
JMH JMH
The International Society of
Blood Transfusion (ISBT)
http://www.bloodbook.com/type-sys.html
5. Lewis
5
The Lewis system focuses on a single locus with 2 antigens, Le a and
Le b.
These antigens do not form an integral part of the red cell
membrane, but are soluble antigens which may be present in body
fluids and secretions.
They are adsorbed on to the surface of red cells if they are present in
the plasma in sufficient amounts.
There are only three phenotypes: Le(a-b-); Le(a+b-); and Le(a-b+).
Lewis phenotypes may change during pregnancy. Examples of
Le(a+b+) are only transient (lasting for only a short time;
impermenant).
Lewis antibodies are only found in Le(a-b-) individuals, and are almost
entirely IgM. They are the only blood group antibodies which have
never been implicated in HDN (hemolytic disease of the newborn.)
6. Lewis Antigens:
Soluble antigens produced by tissues and found in body fluids
(plasma)
Adsorbed on the RBC
Le genes
Le substance in
plasma
RBC
Lewis substance adheres to
RBC becoming an antigen
7. Kell
7
The Kell Systems antigens are found in only small amounts on the red
cell carried on a single protein. The function of this protein is unknown.
Similar to the Rh system
2 major antigens (over 20 exist)
K (Kell), <9% of population
k (cellano), >90% of population
There are also Kp a and Kp b
The Kp(a+) phenotype and the Kp(a-b-) phenotype are both rare.
The Kp(a-b-) is associated with chronic granulomatus disease (CGD), an inherited
defect in the bacterial capacity of neutrophils.
The K and k genes are codominant alleles on chromosome 7 that code
for the antigens.
K has approximately 3500 sites and k has between 2000 - 5000.
Well developed at birth.
The K antigen is very immunogenic (2nd to the D antigen) in stimulating
antibody production.
Antibodies to Kell system antigens are IgG and can be detected by
antihuman globulin serum.
8. 8
MNS
8
There are two loci: M/N and S/s.
Chromosome 4 contains these linked genes.
The antigens are M, N, S, and s.
M & N located on Glycophorin A
S & s and U located on Glycophorin B
Glycophorin is a protein that carries many RBC antigens
Anti-M and anti-N occur in human serum as natural IgM antibodies if
the respective Ag is absent on red cells.
They are IgM antibodies (rarely IgG) and they are clinically insignificant.
Anti-S and anti-s commonly develop immune characteristics (IgG class)
as a result of pregnancy or transfusion.
They are clinically significant and can cause RBC destruction and HDN.
They can be detected by antihuman globulin serum
9. The Duffy system is also a single locus with two antigens, Fya and Fyb.
A pair of predominant genes (co-dominant alleles found on
chromosome 1):
Fya and Fyb code for antigens
Well developed at birth
Biochemically, the Duffy antigens are glycoproteins that has an external
loop. This external loop can be destroyed by enzymes such as ficin,
papain, and trypsin.
Duffy antibodies are almost exclusively IgG.
Anti- Fya and Fyb present in serum invariably as result of immune response
Anti-Fya can cause HDN and Hemolytic Transfusion Reaction (delayed) and anti-Fyb is
milder and no HDN cases have been reported but could possibly be a cause.
They can be detected by AHG serum (React best in Coombs after 37oC incubation)
They are inactivated by proteolytic enzymes (Reactions destroyed by enzyme of the
red cells)
Duffy
9
10. 10
1
Most African-Americans are Fy(a-b-)
This particular phenotype is found up to 100% of western Africa and 68% of the
American Blacks.
Interestingly, certain malarial parasites (Plasmodium sp.) will not
invade Fya and Fyb negative cells
It seems that the Duffy antigens (either Fya or Fyb) are needed for the
malarial parasite to attach (or enter) to the red cell.
The Fya and Fyb antigens are receptors for the malarial
parasite, Plasmodium vivax. Therefore individuals that are phenotypically
Fy(a-b-) have a resistance to malaria.
The Fy(a-b-) phenotype gives a degree of immunity to the disease
The Fy(a-b-) phenotype is found frequently in West and Central
Africans, supporting the theory of selective evolution.
The Duffy and Malaria Connection
12. Kidd
1
2 antigens (co-dominant alleles):
Jka and Jkb
Are inherited on chromosome 18 where urea transport mechanisms are
located.
Well developed at birth
Enhanced by enzymes
Not very accessible on the RBC membrane
The Kidd antigens are thought to be grouped very close together in clusters on
the red cell membrane.
Cells that are Jk(a-b-) are less likely to lyse in the presence of high
concentration of urea. These antigens are inherited by the co-
dominant alleles Jka and Jkb that are high frequency antigens.
13. 1
Anti-Jka and Anti-Jkb :
IgG
Both anti-JKa and anti-Jkb are hard to detect and identify since
they are very weak and are detected primarily at the
antiglobulin phase of testing.
These antibodies are usually low titer as well as being weak
reactions.
Clinically significant Implicated in HTR and HDN (common
cause of delayed HTR)
Usually appears with other antibodies when detected
http://www.bbguy.org/education/glossary/index.aspx?alph
abet=D&id=90
14. 1
Lutheran Blood Group System has 2 co-dominant alleles:
Lua and Lub
Weakly expressed on cord blood cells
Most individuals (92%) have the Lub antigen, Lu(a-b+)
The Lu(a-b-) phenotype is RARE
Anti-Lua
IgM and IgG
Not clinically significant
Reacts at room temperature
Mild HDN
Naturally occurring or immune stimulated
Anti-Lub
Rare because Lub is high incidence antigen
IgG
Associated with transfusion reactions (rare HDN)
Lutheran
