Blood group systems
System
Antigens
Antibodies
Transfusion reaction
HDN
Remarks / diseases
association
-Lea and Leb
- Anti Lea and Leb are IgM
Synthesized in gut epithelium, - React best at temperatures
and released into the plasma
below 37°C
before they adsorb to RBC.
- May be lost from the red cell
surface of stored red cells.
- Not clinically
significant
- Do not cause HDN.
- Leb antigen is a receptor
for Helicobacter Pylori and
may be associated with the
development of peptic
ulcers and stomach
cancer.
P system
- P1
- Frequency of P1:79% in
white population and
93% in the black population
- Not fully expressed in fetal
RBC.
- Anti P1 is IgM. Antibody.
- Cold reacting Ab but
occasionally react @ 37 C.
- Usually not clinically
significant.
-Rare example may
bind complement and
cause transfusion
reactions.
- Has not been
reported to cause
HDFN
- Antigen found on urinary
tract epithelium where it
may act as a receptor for
microorganisms such as
Escherichia coli.
- Involved in urinary tract
infections.
I system
- Two Ags: I and i.
- Fetal and neonatal red cells
express the i antigen with little
I antigen. However, during the
first 18 months of life, the
expression of i slowly
decreases and the expression
of I increase.
- Most adults RBCs express I
and neonatal RBCs express i.
- Anti I is IgM antibody.
- Cold reacting Abs.
- May exist as autoantibodies
and cause auto immune
diseases
Usually not clinically
significant
- Has not been
reported to cause
HDFN
Lewis
Blood group systems
System
Antigens
MNS
system
- 43 antigens
- the most important are M, N,
S, and s.
- The MN antigens are situated
on glycophorin A (GPA) and
the Ss antigens on glycophorin
B (GPB)
- Anti MN are usually IgM.
- Anti S,s are usually IgG.
- Uncommon but
potentially severe.
-Anti-S and anti-s are
among the MNS
antibodies implicated
in causing
transfusion reactions.
- Uncommon but
potentially severe
- Anti-S is more
common than anti-s,
but both are capable
of causing
severe-to-fatal HDN
Lutheran
system
- Two major antigens: Lua and
Lub.
- They are poorly developed at
birth and poorly immunogenic.
- Lub is a high frequency
antigen whereas Lua is a low
frequency antigen.
- Anti Lua and Lub
- May cause mild or
delayed transfusion
reaction.
- Anti Lua and Lub
have not been
reported to cause
HDFN.
- Antigen found on urinary
tract epithelium where it
may act as a receptor for
microorganisms such as
Escherichia coli.
- Involved in urinary tract
infections.
- Anti-K and anti-k are
usually type IgG antibodies.
- If a patient develops anti-k
it will be difficult to provide
compatible blood because of
the low frequency of kblood.
- anti-k, anti-Kpa, and
anti-Jsb have been
implicated in causing
transfusion reactions.
- Anti-K and Ku can
cause sever reaction.
- K- or k- blood should
be provided to patients
with anti-K or anti-k
antibodies, respectively
Anti-Kell is an
important cause of
HDN.
- It tends to occur in
mothers who have
had several blood
transfusions in the
past, but it may also
occur in mothers who
have been sensitized
to the Kell antigen
during previous
pregnancies .
- Anti-K antibodies differ
from other blood group
system antibodies that
cause HDN as the
antibodies appear to
destroy precursor red cells,
causing severe fetal
anaemia.
Kell system - 28 antigens.
- The most important are: K
and k, Kpa , Kpb , Jsa and Jsb .
-The K antigen is the most
immunogenic antigen after the
antigens of the ABO and Rh
blood group systems.
- Kell antigens are well
developed at birth.
- Most frequent phenotype is
K- k+.
Antibodies
Transfusion reaction
HDN
Remarks / diseases
association
- Glycophorins A and B
may act as a receptor for
Plasmodium falciparum.
System
Duffy
system
Antigens
-
-
-
Kidd
system
Contain six antigens,
the most important are
Fya and Fyb.
The Duffy antigens are
moderately
immunogenic and are
well developed at birth
The minus/minus
phenotype, Fy(a-b-), is
more common in
blacks.
- antigens are expressed on a
red cell transmembrane
glycoprotein which transports
urea across the red cells
membrane.
- The two important antigens
are: Jka and Jkb.
- well developed in the
newborn.
Antibodies
Transfusion reaction
HDN
- Anti-Fya and anti-Fyb are
type IgG (stimulated
by transfusion or pregnancy)
- Can cause severe
transfusion reactions.
- Can cause sever
HDN.
- IgG antibodies that can
activate complement.
-
- Can cause sever
transfusion reactions.
- Rarely cause HDN.
Remarks / diseases
association
Duffy antigens are the site
of attachment to the red
cell for the malarial
parasites Plasmodium
vivax and P. knowlesi.
- individuals with FY(a-b-)
are resistant to those
parasites.