ABO blood group system was decover by Karal landsteine
which contain A, B, and o antigen on the surface of BC, WBC,s platatelet and other body tissue cells except brain cell, and anti A, antiB and Anti Ab natural occuring antibodies in plasma of B,A, and O blood group individual respectively
3. History - Karl
Landsteiner
Discovered the ABO Blood
Group System in 1901
He and his five co-workers
began mixing each others red
cells and serum together and
inadvertently performed the
first forward and reverse ABO
groupings
4. Landsteiners
Rule
Karl Landsteiner’s law :
If an antigen is present in the RBC’s of an
individual, the corresponding antibody
must be absent from the plasma
If an antigen is absent in the RBC’s of an
individual, the corresponding antibody
must be present from the plasma
’.
6. ABO Basics
Blood group antigens are actually sugars
attached to the red blood cell.
Antigens are “built” onto the red cell.
Individuals inherit a gene which codes for
specific sugar(s) to be added to the red
cell.
The type of sugar added determines the
blood group
7. Principle of
blood
grouping
There are two principles
1-almost all normal healthy individuals above 3-6
months of age have “ naturally occurring Abs” to
the ABO Ags that they lack
These Abs termed naturally occurring because they
were thought to arise without antigenic stimulation
8. Principle of
blood
grouping
2- These “naturally occurring” Abs are mostly IgM
class. That means that, they are Abs capable of
agglutinating saline/ low protein suspended red
cell without enhancement and may activate
complement cascade.
9. ABO and H
Antigen
Genetics
ABO chromo
9
O gene on
chrom 19
Ags belonging to ABH blood group system are
present on RBCs and other body cells and body
fluids.
The presence of A,B, and O Ags on RBCs depends
upon the allelic genes, A,B, and O
An H genes at a separate locus codes for the
precursor substance on which the A and B gene
products act
The products of the A and B genes are enzymes that
act as a specific transferases
10. Genetics
The ABO genes do not code for the production of
ABO antigens, BUT rather produce specific glycosyl
transferases
ABO produces a specific glycosyl transferases that
add sugars to a basic precursor substance on the
RBCs
12. There are two potential precursors substance (PS)
both are comprised of identical sugar (galactos-N-
acetyl gluctosamin - galactose -glucose) but
different in linkage.
Type I PS has a terminal galactose (Gal) linked to a
subterminal N acetylgucoseamine (GlcNAc) in 1-3
linkage
Type II PS, has the same sugar combine in 1-4
linkage
ABH Ags on RBCs are derived from Type II chains
13. HAntigen
The inheritance of at least one H gene (HH or Hh)
elicits (obtain) the production of an enzyme called,
α-2-L-Fucosyl transferase, which transfers the
sugar from the Guanosine diphosphate L-fucose
(GDP-Fuc) donor nucleotide to the terminal
galactose of the precursor chain.
The H substance must be formed for the other
sugars to be attached in response to an inherited A
and /or B genes
14. Formation of
the H antigen Glucose
Galactose
N-acetylglucosamine
Galactose
Precursor
Substance
(stays the
same)
RBC
H antigen
Fucose
15. A and B
Antigen
The “A” gene codes for an enzyme (transferase) that
adds N-acetylgalactosamine to the terminal sugar of
the H antigen
N-acetylgalactosaminyltransferase
The “B” gene codes for an enzyme that adds D-
galactose to the terminal sugar of the H antigen
D-galactosyltransferase
16. Formation of
theA antigen Glucose
Galactose
N-acetylglucosamine
Galactose
RBC
Fucose
N-acetylgalactosamine
A antigen
17. Formation of
the B antigen Glucose
Galactose
N-acetylglucosamine
Galactose
RBC
Fucose
Galactose B antigen
19. Formation of
the H antigen Glucose
Galactose
N-acetylglucosamine
Galactose
Precursor
Substance
(stays the
same)
RBC
H antigen
Fucose
O antigen
20. H antigen
Certain blood types possess more H antigen than
others:
O>A2>B>A2B>A1>A1B
21. Genetics
The H antigen is found on the RBC when you have the
Hh or HH genotype, but NOT from the hh genotype
The A antigen is found on the RBC when you have the
Hh, HH, and A/A, A/O, or A/B genotypes
The B antigen is found on the RBC when you have the
Hh, HH, and B/B, B/O, orA/B genotypes
22. Bombay
Phenotype
(Oh)
Inheritance of hh
The h gene is an amorph and results in little or no
production of L-fucosyltransferase
Originally found in Bombay
Very rare (130 worldwide)
23. Bombay
Phenotype
(Oh)
The hh causes NO H antigen to be produced
Results in RBCs with no H, A, or B antigen (patient
types as O)
Bombay RBCs are NOT agglutinated with anti-A, anti-
B, or anti-H (no antigens present)
Bombay serum has strong anti-A, anti-B and anti-H,
agglutinating ALL ABO blood groups
What bloodABO blood group would you use to
transfuse this patient??
Another Bombay
Group O RBCs cannot be given because they still
have the H antigen
You have to transfuse the patient with blood that
contains NO H antigen
24. ABO
antibodies
GroupA serum contains anti-B
Group B serum contains anti-A
GroupAB serum contains no antibodies
GroupO serum contains anti-A, anti-B, and anti-A,B
25. ABO
antibodies
IgM is the predominant antibody in GroupA and Group
B individuals
Anti-A
Anti-B
IgG (with some IgM) is the predominant antibody in
GroupO individuals
Anti-A,B (with some anti-A and anti-B)
26. ABO
antibodies
Reactions phase: Room temperature
Complement can be activated with ABO antibodies
(mostly IgM, some IgG)
High titer: react strongly (4+)
Usually present within the first 3-6 months of life
Stable by ages 5-6 years
Decline in older age
Newborns may passively acquire maternal antibodies
(IgG crosses placenta)
Reverse grouping (with serum) should not be performed on
newborns or cord blood
27. ABO
routine testing
Several methods for testing the ABO group of an
individual exist.The most common method is:
Serology: This is a direct detection of the ABO
antigens. It is the main method used in blood
transfusion centres and hospital blood banks.
This form of testing involves two components:
a) Antibodies that are specific at detecting a particular
ABO antigen on RBCs.
b) Cells that are of a known ABO group that are
agglutinated by the naturally occurring antibodies in
the person's serum.
28. ABO
ROUTINE
TESTING
DIRECT OR FORWARD GROUPING
Test for antigens
• Patient’s cells containing unknown antigens tested
with known antisera
• Antisera manufactured from human sera
Aantisera used:
Antisera Color Source
Anti-A Blue Group B donor
Anti-B Yellow Group A donor
Anti-A,B Red Group O donor
29. Forward
Grouping
Reaction of patient red blood cells tested with
Reagent anti-A and anti-B antisera
Slide: 20-40% RBC suspension + anti-serum
Tube (12x75mm): 2-5% RBC suspension + anti-serum
(centrifuge before read)
31. Reverse
grouping
• serum is combined with cells having known Ag
content in a 2:1 ratio
• uses commercially prepared reagents containing
saline-suspended A1 and B cells
33. Grading of Agglutination:
Negative (0) No clumps or aggregates
Weak (+/-) Tiny clumps or aggregates barely
visible macroscopically or to the
naked eye
1+ Few small aggregates visible
macroscopically
2+ Medium-sized aggregates
3+ Several large aggregates
4+ One solid aggregate
38. Forward &
reverse
ABO blood
grouping
Reaction of CellsTested With
Reaction of SerumTested
Against ABO
Group
Anti-A Anti-B A1 Cells B Cells
1 0 0 + + O
2 + 0 0 + A
3 0 + + 0 B
4 + + 0 0 AB
40. ID card
system
This ID-Card contains a mixture of human polyclonal
and monoclonal anti-A, human polyclonal anti-B and
human polyclonal anti-D antibodies.
The microtube ctl is the negative control.Two
microtubes with neutral gel serve for reverse grouping
with A1 and B cells.