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Compatibility Testing for Blood
Transfusion
RIH Department of
Anesthesiology
What’s new?
How much
ONeg Blood
Is OK?
Why does it
take so much
time?
What are our
transfusion policies ?
Blood Bank Issues
ISBT = International Society
of Blood Transfusion
Recognizes the Presence of Multiple
Antigens on the Surfaces of
Red Blood Cells that define
Blood Group Systems
BLOOD GROUP SYSTEMS
CONVENTIONAL NAME
*ABO
MNSs
P
*Rh
Lutheran
Kell
Lewis
Duffy
Kidd
Diego
Cartwright
ISBT SYMBOL
ABO
MNS
P1
RH
LU
KEL
LE
FY
JK
DI
YT
ISBT NUMBER
ANTIGENS
001
002
003
004
005
006
007
008
009
010
011
4
37
1
47
18
21
3
6
3
2
2
BLOOD GROUP SYSTEMS
CONVENTIONAL NAME
ISBT SYMBOL
Xg
Scianna
Dombrock
Colton
XG0
SC
DO
CO
LW
CH/RG
H
XK
GE
CROMER
KN
IN
OK
RAPH
JMH
Landsteiner-Wiener
Chido/Rogers
Hh
Kx
Gerbich
Cromer
Knops
Indian
Ok
Raph
JMH
ISBT NUMBER
012
013
014
015
016
017
018
019
020
021
022
023
024
025
026
ANTIGENS
1
3
5
3
3
9
1
1
7
10
5
2
----
Population Distribution of
Major Blood Groups
O
O
A
A
B
B
AB
AB
Rh pos
Rh neg
Rh pos
Rh neg
Rh pos
Rh neg
Rh pos
Rh neg
38%
7%
34%
6%
9%
2%
3%
1%
Why do we care?
Compatibility testing is done to avoid
a hemolytic transfusion reaction
If the Host or Recipient recognizes
the donor RBC surface antigens as foreign,
the host will mount an immune response
to the donor RBC’s
Major Blood Groups
ABO
ABO blood group antigens
present on red blood cells
and IgM antibodies
present in the serum
Why do we have Anti-A or Anti-B
Antibodies???
They are not present in the newborn
They develop in the first years of life
Exposure to plant, bacterial, viral
antigens provokes this response
Why do we have Anti-A or Anti-B
Antibodies???
Viruses transmitted from the
respiratory tracts of humans to other
humans drag along various antigens
including ABO blood group antigens.
Prime the newborn’s immune system.
Reduces transmissibility of viruses
within a population.
Major Blood Groups
Rhesus
47 Antigens make up the
Rhesus Blood Group
The most significant is the
D antigen
There is no naturally occurring
Anti D
Production of Anti D in the
RH negative recipient
requires previous exposure
to the D antigen
(in utero or by transfusion)
If red cells are administered
to an ABO- or D-incompatible recipient,
the recipient will mount an
antibody response to the foreign
RBC surface antigens
IgM is polyvalent
and fixes complement
Intravascular Clumping of Donor RBC’s
Intravascular hemolysis of donor RBC’s
Clumps and extruded RBC stroma
result in organ dysfunction
and possible death
Incidence 1:38,000 – 1:70,000
Mortality 1:30
Other Blood Groups
No naturally occurring antibodies
Immune response requires
previous exposure
Weaker titers of univalent antibodies
Donor RBC’s coated with host antibodies
Stiffer RBC membrane
Susceptible to attack by
splenic macrophages
But no
intravascular clumping
Bits of Donor RBC membrane
lost traversing splenic sinusoids
(extravascular hemolysis)
Spherocytes
Decreased RBC survival
Delayed anemia
Priming for worse reaction
Donor
Questionnaire:
Medical history
Lifestyle
Finger stick:
Checking Hct
Donor
Needs a Hct of 0.38
A drop of donor blood is placed into a
test tube containing a
CuSo4 solution
CuSo4 solution has a SG of 1.053
RBC with Hct > 0.38 sink to
the bottom of the test tube
Donor
Side sample (20cc) collected for testing:
Blood group and Infection
The bag is anticoagulated
The unit is labeled with a lot#
like any drug
e.g. LH59321
DIFFERENT LEVELS OF COMPATIBILITY
TESTING
Landsteiner,
1899
Lifespan, 2008
COMPATIBILITY TESTING
The purpose of pre-transfusion
compatibility testing is to PREVENT
hemolytic transfusion reaction
Clerical and technical components
Samples must be labeled at the bedside
Two methods of ID required:
Name, SSN, MR#, DOB
The phlebotomist must sign the tube
COMPATIBILITY TESTING
Lab checks:
Identity
Record of previous specimen
Record of previous ABO-Rh type
History of abnormalities
COMPATIBILITY TESTING
Processing the specimen:
ABO Group determined (forward and
reverse)
D typing determined
Antibody screen will be performed
ABO/Rh identical or compatible blood will
be made available
ABO TYPING
Front or forward type using monoclonal antiA and anti-B (commercial)
The sample is diluted to Hct 0.08, the
commercial antibodies added & the test
tube is centrifuged
The RBC’s are then examined for clumping
(gross observation, gel suspension)
Anti A
Anti B
A
Anti B
Anti A
Anti B
B
Anti A
AB
Anti A
Anti B
O
ABO TYPING
Back or reverse type with A and B cells
Commercially available A and B cells are added to
two tubes of plasma
AB
A
B
B
A
A
B
A
O
B
A
B
How do we know whether or not the host (or
recipient) has antibodies to minor blood
group antigens?
Add commercial RBC’s with known important
minor antigens on their surface to host (or
recipient) plasma and centrifuge. Then
incubate at body temperature for 15-30
minutes
Then add rabbit antiglobulin
If recipient antibodies have coated
commercial RBC surfaces
Rabbit antiglobulin will bind to the
Antibodies and the RBC’s will clump
ANTIBODY SCREENING
Detection of unexpected clinically significant
antibodies against the minor blood group
system antigens
Also called the indirect Coombs test or the indirect
antiglobulin test
Positive in between 0 - 8% of samples depending
on the population
Possibly significant minor blood groups
MNSs
P
*Rh
Lutheran
Kell
Lewis
Duffy
Kidd
Diego
Cartwright
MNS
P1
RH
LU
KEL
LE
FY
JK
DI
YT
002
003
004
005
006
007
008
009
010
011
37
1
47
18
21
3
6
3
2
2
SCREENING TEST RESULTS
A negative antibody screen allows blood
to be dispensed using an immediate spin
X-match or an electronic X-match, either
of which confirms ABO compatibility
A positive antibody screen requires a full
antiglobulin phase X-match
POSITIVE ANTIBODY SCREEN
Can some or all of the antibodies be
identified?
Identify red cells which lack these
antigen(s)
Why does it
take so much
time?
Why does it take so long?
Sample collection
Specimen transport
Specimen centrifugation
Testing
15”
25”
How much
ONeg Blood
Is OK?
How much ONeg?
Past data from Vietnam war era
Minimal auto antibodies in universal
donor blood
Per Dr. Sweeney > 80 units before
anti-A and anti-B cause problems
What are our
transfusion policies ?
Policies
Consent:
Covered in surgical
consent
Prescription: Needs to be ordered
Collection: Label blood at bedside
Name, MR #, other
Sign and date
Policies
Administration:
Inspect bag
Verify ABO Rh
Match ID’s
If no access to name bracelet use
Innovian to match ID’s
2 licensed personnel & 2 signatures
Normal saline only
What’s new?
What’s new?
2007 Nature Biotechnology
USA, Denmark, France, Sweden
Convert blood types A, B, and AB
to O, using bacterial glycosidase
enzymes to cleave the antigens
from the RBC surface.
Need D negative cells
Red blood cell compatibility table
Recipient
Donor
O- O+ A- A+ B- B+ AB- AB+
OO+
AA+
BB+
ABAB+
Plasma compatibility table
Recipient
Donor
O A B A
B
AB
A
B
O