II. BLOOD GROUP SYSTEMS
III. LANDSTEINER’S LAW
IV. CLASSICAL ABO BLOOD GROUPING SYSTEM
V. RHESUS BLOOD GROUPING SYSTEM
VI. CLINICAL IMPLICATION OF BLOOD GROUPING
VII. BLOOD TRANSFUSION
Austrian Karl Landsteiner(1900) discovered -
•Human blood possess different antigenic and immune properties
•Blood clumping was an immunological reaction.
Nobel Prize in Physiology and Medicine in 1930.
Major blood group system
Minor blood group system
Familial blood group system-
Kell, Duffy, Lutheran, Lewis, Deigo, kidd Etc.
Blood Group System
1.If an agglutinogen is present on red blood cell membrane ,the corresponding agglutinin
must be absent in the plasma.
2.If an agglutinogen is absent on red blood cell membrane, then corresponding agglutinin
must be present in the plasma.
II. Antigen and Antibodies
ABO Blood Group System
• Karl Landsteiner(1900) classified human blood into A,B,O groups.
• Von Decastello and Sturli (1902) discovered AB blood group.
• Von Dungern and Hirszfeld(1911) divided group A into 2 subgroups A1 and A2.
Appear in the sixth week of fetal life.
Present on red cell membrane and in other tissues like salivary glands, pancreas, kidney
EXCEPT CNS also in body fluids.
H antigen is also present usually in all individuals.
Formation of H Antigen
L Fucosyl Transferase Enzyme (product of H gene)
N-acetylgalactosaminyl Transferase (product of A gene)
Formation of the A antigen
Formation of the B antigen
D-galactosyl Transferase(product of B gene)
Group O Group A
Many H antigen sites
Why do Group O individuals have more
H antigen than the other groups?
The O gene is a silent allele. It does not alter the
structure of the H substance….that means more
H antigen sites.
• Mostly IgM type.
• Produced by bone marrow and lymph gland cells .
• Known as cold antibodies.
Anti-A and Anti-B agglutinins
Titre of antibodies
Why antibodies produced in people who do not have the
respective antigens in their red blood cells?
Immune system form antibodies against the antigens recognised as non-self(i.e. not
present in the own body).
Alpha -agglutinins- alpha-1 and alpha -proper.
20% 40% 8% 32%
Group A has 2 subgroups -A1 and A2.
Group AB -A1B and A2B.
Types of ABO Blood Group
Inheritance of ABO blood group
Follows Mendelian Law.
In 1924, Felix Bernstein proposed presently accepted theory.
Heterozygous: AO or BO
Homozygous: AA or BB
Mom Dad Offsprin
AA BB 100%
BO OO 50%
B or O
OO OO 100% O
OO AO 50%
A or O
Genotype And Phenotype
ANTIGEN ANTIBODY GENES at
GENES at 19
A A Anti-B AA,AO HH
B B Anti-A BB,BO HH
AB AB None AB HH
O Neither(H) Anti-A and
The Rhesus Blood Group System
I. Discovery of Rh system
II. Antigen and antibodies
IV. Haemolytic disease of newborn
History of the Rh System
Levine and Stetson(1939) described a hemolytic transfusion reaction in an obstetric
patient following delivery of stillborn infant.
An antibody was isolated from the mother’s serum. It was postulated that the fetus and the
father possessed a common factor that the mother lacked.
While the mother carry the fetus, the mother was exposed to this factor and developed
antibody against the transfused red cells from the father and resulted in transfusion
At that time ,the responsible antibody was not named.
Landsteiner and Wiener(1940) injected RBC’s of rhesus monkeys in rabbits- developed
The antibody was named as anti-Rh.
When resulting antiserum was mixed with human RBC’s, then agglutination occurred.
The RBC antigen responsible for this reaction was called as Rh factor.
The antibody discovered by Levin and Stetson in the mother was subsequently re-
examined and found identical in activity as the anti-Rh antibody found by Landsteiner and
So this work led to discovery of Rh system.
Anti-rhesus formed by the animals was renamed anti-LW (Landsteiner and Wiener).
Fisher and Race(1943 and 1944) discovered C, E, c, e Ag and their corresponding antibodies
anti-C , anti -E ,anti- c ,anti -e.
• Rh system involves 6 Rh
Presence of rh D
Absence of rhD
Integral membrane proteins with an active phoshpholipid component.
Present on red blood cells.
D antigen is commonest and most immunogenic.
• IgG type.
• Known as warm antibodies.
• Produced by exposure to foreign Rh antigen .
• D Ag is inherited as a dominant gene D.
• Genotype of individual may be:
• ABO Incompatibility- immediate reaction as antibodies are naturally present.
• Rh Incompatibility-
Immediate and severe response.
But Rh antibody is produced
To Rh negative personFrom Rh positive person
Rh antigen reacts with Rh antibody
Mechanism- Rapid production of red blood cells by haematopoeitic tissues of baby in order
to replace haemolysed RBC’s.
II.Icterus gravis neonatorum
I. Anti-D Prophylaxis –
• Based on principle antibody mediated immunosuppression.
• Inject anti-D antibody in mother soon after child birth.
• Fetal Rh typing, then give anti- D antibody to expectant mother between 28 to 30 weeks.
II. Exchange transfusion
Prevention And Treatment
• THE Ii SYSTEM-
Weiner et al (1956)
2 antigens –I and i
• At birth , RBC’s are rich in i Ag ,not I Ag.
• In first second years of life, gradual changeover from i to I.
Other Blood Group Systems
• THE DUFFY SYSTEM
Cutbush , Mollison and Parkin(1950).
System has 3 blood groups-Fya ,Fyb and Fyab.
Fyab blood groups are resistant to plasmodium vivax whereas Fya and Fyb are susceptible
to vivax malaria.
• KELL SYSTEM-
Coombs ,Mourant , Race(1946).
Antigen - K
Rare In India(.3 To .7%)
• P BLOOD GROUP SYSTEM-
Landsteiner and Levine in(1927).
2 blood groups- P positive
• MN SYSTEM-
Landsteiner and Levine(1927).
• Paternity tests
• Anthropological and genetic studies.
• LEWIS SYSTEM-
Mourant and Andresen(1946,1948)
2 antigens- Lea and Leb.
Ceppelline(1955) showed, Lea substance in saliva was controlled by dominant gene Le
and its allele le.
Not real antigens because they are present in plasma and saliva, RBCs acquire by
adsorption from plasma.
I. In blood transfusion.
II. In preventing HDN due to Rh Incompatibility.
III. In paternity disputes.
IV. In medicolegal cases.
V. In knowing susceptibility to diseases.
II. Donor and Recepeints
I. Blood loss.
II. For quick restoration of Hb.
III. Exchange transfusion.
IV. Blood diseases like- aplastic anaemia, leukaemia,hemophilia,purpurae,clotting defects.
V. Acute poisoning.
VI. Acute infections or fever when gamma globulin is needed.
• Donor selection-
I. Healthy and age between 18 to 60 years.
II. Haemoglobin > 12 gm%
III. Weight more than 45 kg.
IV. Females should not be Pregnant, lactating and menstruating.
V. No diseases like AIDS, Viral Hepatitis ,Malaria, Syphilis.
VI. No past H/O jaundice , HTN,TB, and cardiac diseases.
Donor And Recepient
Blood transfusion-who can receive
blood from whom?
Antigens Antibodies Can give
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
• For safe and compatible blood transfusion-
• ABO and Rh typing
• Cross matching
• Antibody screening
Human RBC before (left) and after (right) adding serum containing antibodies.
II. Cross Matching-
Major cross matching -Donor’s RBCs are mixed with recepient’s plasma.
Minor cross matching- Recepients RBC’s are mixed with donor’s plasma.
When no agglutination then only donors blood can be transfused.
IV. Rh positive blood should never be transfused to Rh negative blood.
V. Check blood bag for correct label.
VI. Transfuse blood at slow rate(not >20 drops/min) under proper aseptic measures.
VII. Careful watch on recepient’s condition.
VIII. Stop transfusion if reaction occurs.