Blood groups ABO
and Rhesus
PROF.AIJAZ QURESHI
Learning Objetives
At the end of lecture students will able to
Define agglutinogens and agglutinins
Understand inheritane of antigens and
development of antibodies
Know universal recipient and donars
Know the types ob blood groups
Define erythroblastosis fetalis, its
prevention and treatment
•The differences in human blood are due to the
presence or absence of certain protein molecules
called antigens and antibodies.
•The antigens are located on the surface of the
RBCs and the antibodies are in the blood plasma.
•Individuals have different types and
combinations of these molecules.
•The blood group you belong to depends on
what you have inherited from your parents.
• There are more than 20 genetically determined
blood group systems known today
• The AB0 and Rhesus (Rh) systems are the
most important ones used for blood transfusions.
The ABO System
Discovered in 1901 by Dr.
Karl Landsteiner
ABO gene located on long arm
of chromosome 9
ABO blood grouping system
According to the ABO blood
typing system there are four
different kinds of blood types: A,
B, AB and O.
AB0 blood grouping system
Blood group A
If you belong to the blood
group A, you have A
antigens on the surface of
your RBCs and B
antibodies in your blood
plasma.
Blood group B
If you belong to the blood
group B, you have B
antigens on the surface of
your RBCs and A
antibodies in your blood
plasma.
Blood group AB
If you belong to the blood group
AB, you have both A and B
antigens on the surface of your
RBCs and no A or B antibodies
at all in your blood plasma.
Blood group O
If you belong to the blood group O,
you have neither A or B antigens on
the surface of your RBCs but you have
both A and B antibodies in your blood
plasma.
ABO Antibodies
A and B substances are very common
Antibodies produced to “non-self”
Produced after first few months of
life (2 to 8 months, reach maximum
titer 8 to 10 years
A & B people have mainly IgM
O people have IgG
Fade in old age
ABO inheritance and genetics
• The ABO gene is autosomal (the gene is not on either sex
chromosomes)
• The ABO gene locus is located on the chromosome 9.
• A and B blood groups are dominant over the O blood group
• A and B group genes are co-dominant
• Each person has two copies of genes coding for their ABO blood
group (one maternal and one paternal in origin)
Antigens & Antibodies
Blood Antigens on
Antibodies in Serum Genotypes
Group RBCs
A A Anti-B AA or AO
B B Anti-A BB or BO
AB A and B Neither AB
O Neither Anti-A and anti-B OO
Blood transfusions – who can
receive blood from
whom?
People with blood group O
are called "universal
donors" and people with
blood group AB are called
"universal receivers."
Blood Antigens Antibodies Can Can
Group donate receive
blood to blood from
AB A and B None AB AB, A, B, O
A A B A and AB A and O
B B A B and AB B and O
O None A and B AB, A, B, O O
The Rh(D) Antigen
Discovered in 1940 after work
on Rhesus monkeys
Rh gene located on short arm of
chromosome 1
Six types of Rh antigens C, D, E,
c, d, e
D is more antigenic
Simple Genetics of Rh(D)
86% of caucasians are Rh(D) pos
The d gene is recessive:
Dd, dD, DD, persons are Rh(D) pos
Only dd persons are Rh(D) neg
Inheritance
ABO & Rh genes are not linked
ABO & Rh(D) type are inherited
independently
For example:
An A Rh(D) pos mother
and a B Rh(D) pos father
could have an O Rh(D) neg child
Inheritance
Rh negative person can produce anti-D
antibody when expose to antigen D
Anti-D antibody will not develop without
exposure to antigen D
To develop anti-D, need transfusion
- From other person
- From fetal blood to mother (Anti-D
belong to IgG & capable of crossing the
placenta)
• A person with Rh- blood can develop Rh antibodies in
the blood plasma if he or she receives blood from a
person with Rh+ blood, whose Rh antigens can trigger
the production of Rh antibodies.
•A person with Rh+ blood can receive blood from a
person with Rh- blood without any problems.
Rh system
Rh immune response
Delayed transfusion reaction—
usually mild
Spontaneous transfusion reaction
never occur
HEMOLYTIC DISEASE OF
NEWBORN (HDN)
ERYTHROBLASTOSIS FOETALIS
A severe hemolytic disease of a fetus or
newborn infant caused by the production
of maternal antibodies against the fetal
red blood cells, usually involving Rh
incompatibility between the mother and
fetus.
Clinical Picture
Antibodies cause destruction of the red
cells
Anemia
Heart failure
Build up of bilirubin
Kernicterus
Severe mental retardation
.Nucleated blast
forms of RBC
THANK YOU
