Undergraduate Course in Veterinary Clinical
PathologySocrates Programme
Haematology
LECTURE 10.
BLOOD GROUPS AND
TRANSFUSIONS
10-1
OVERVIEW
1. Blood Group Systems
2. Blood group testing and cross-matching
3. Definition, aims and indications for blood
transfusion
10-2
1. BLOOD GROUP
SYSTEMS
10-3
Page 1
BLOOD GROUP SYSTEMS
In Simple Terms:
Blood groups are determined according to the
antigens expressed on the erythrocyte
Combinations of blood groups make up a blood
group system
HOWEVER:
Antibodies against different blood group antigens
are extremely important in determining the
success or failure of a blood transfusion
10-4
RED BLOOD CELL ANTIGENS:
GENERAL CHARACTERISTICS
- Generally glycoproteins or glycolipids anchored
to the surface of the erythrocyte
- Usually detected by antibodies (naturally
occurring or induced by deliberate
immunisation)
- Grouped in blood group systems encoded by
alleles at single or multiple gene loci
10-5
BLOOD GROUP ANTIBODIES:
GENERAL FEATURES
- The presence of antibodies directed against RBC
antigens will reduce survival of transfused cells
(transfusion reaction)
- Some species have high titres of naturally-occurring
antibodies which mayy cause transfusion reactions
after the first transfusion
- Antibodies can be induced following a transfusion.
Therefore the risk of transfusion reactions in
subsequent transfusions is greater
- Neonates can receive these antibodies in colostrum
causing neonatal isoerythrolysis
10-6
Page 2
BLOOD GROUP SYSTEMS: DOGS
- Dogs have 14 blood groups
nomenclature Blood group
DEA
prevalence
in dogs (%)
determined by the Dog
Erythrocyte Antigens (DEA)
- DEA 1.1, DEA 1.2, and DEA 7
are the most immunogenic
- Naturally occcuring antibodies
are rare
- Reactions rarely occur after first
un-matched transfusions
1.1 (A)
1.2
1.3
3 (B)
4 ((C))
5 (D)
6 (F)
7 (Tr)
(o)
J
K
L
M
N
10-40
4-9
9-20
6
100
22
100
10-40
31
34
2
51
19
62
10-7
BLOOD GROUP SYSTEMS: CATS
- Cats have A, B and rarely AB blood groups
- Prevalence of blood groups varies between countries
and with breed
Blood
Reaction
group
A
with
anti-A
B
anti-B
AB
anti-A &
anti-B
Natural antibodies blood group
in serum
frequency prevalence
type
anti-B
rare
very high
80 - 90%
anti-A
high
low
10 - 20%
absent
absent
rare
Transfusion reactions can occur after first transfusion due to
naturally occurring antibodies
10-8
BLOOD GROUP SYSTEMS
HORSE
CATTLE
- Horses have up to 33
different blood groups
belonging to 7 systems
- Cattle have up to 70
different blood groups
belonging to 11 systems
- Aa, Qa, and Ca are the
most immunogenic
blood groups
- The J blood group
system is not a true RBC
antigen but adsorbed
from plasma
Alloantibodies are produced following transfusion
in at least 50% of recipients
10-9
Page 3
2. BLOOD GROUP TESTING
(BLOOD TYPING) AND
CROSS-MATCHING
10-10
BLOOD GROUP TESTING
(BLOOD TYPING)
- Detects the antigens pattern on the erythrocyte
surface using polyclonal or monoclonal antisera
- Does not determine the presence of antibodies
10-11
BLOOD GROUP TESTING:
DOGS AND CATS
THIS DOG IS NEGATIVE FOR
DEA 1.1
THIS CAT IS TYPE AB (RARE)
10-12
Page 4
BLOOD GROUP TESTING
HORSE AND/OR COW
AGGLUTINATION TEST
HAEMOLYSIS TEST
10-13
BLOOD CROSS-MATCHING (BCM)
• Assess blood compatibility between the donor and
the recipient
• A simple technique without any specific reagent
• Major cross-match detects if the recipient’s serum
contains any antibodies against the donor’s RBCs
• Minor cross-match detects if the donor’s serum
contains any antibodies against the recipient’s RBCs
10-14
CROSS MATCHING TECHNIQUE
- Collect a blood sample both from donor and recipient into
anticoagulant (EDTA or heparin)
- Centrifuge the samples, remove and retain the plasma
- Resuspend RBCs in saline, centrifuge, and discard the
supernatant; repeat 3 times (washed RBC).
- Prepare a 3-5% RBC suspension with saline
MINOR CROSS-MATCH
MAJOR CROSS-MATCH
Mix recipient RBC suspension
with plasma from the donor
(ie two drops each)
Mix donor RBC suspension
with plasma from the recipient
(ie two drops each)
- Incubate at 3 different temperature (37°C, 20°C, and 4°C)
- Check after 15-30 minutes for haemolysis and/or agglutination
by visual inspection or eventually microscopically
10-15
Page 5
Haem
Haem
Cont
Aggl
C
Cont
Aggl
CROSS-MATCH (CM) TEST ON SLIDES
CROSS-MATCH (CM) TEST ON TUBES
10-16
3. DEFINITION, AIMS AND
INDICATIONS FOR
BLOOD TRANSFUSION
10-17
BLOOD TRANSFUSION: DEFINITION
AND AIMS
Definition:
A form of temporary organ transplantation
Must respect the blood group systems of the species
and the individual
A useful symptomatic treatment in many blood
disorders
Aims:
- Supplying oxygen to body tissue
- Restoring the blood volume
10-18
Page 6
BLOOD TRANSFUSION: MAIN
INDICATIONS
- Severe and/or acute anaemia:
• Haemorrhagic
• Haemolytic
H
l ti
• Non regenerative
- Severe coagulopathy
- Severe thrombocytopenia
10-19
BLOOD AND BLOOD PRODUCTS
- Whole Blood: fresh or stored (FWB or SWB)
- Packed Red Blood Cells (PRBC)
- Plasma:
• fresh frozen (FFP)
• frozen (FP)
• cryoprecipitate (Cryo) + cryosupernatant
- Platelet rich plasma or concentrate (PLTC)
10-20
BLOOD AND BLOOD PRODUCTS:
ACTIVITIES
Source of FWB SWB PRBC
or activity
Supernatant
FFP
FP
PLTC
Cr yo
RBC
+++
++
++
---
---
---
---
---
Album in
+++
+++
+/-
+++
+++
---
---
+++
PLT
+++
---
---
---
---
+++
---
---
FII,VII,IX,X
+++
---
---
+++
++
---
---
++
FVIII,vWF
+++
---
---
+++
---
---
+++
+/-
ATI I I
+++
---
---
+++
+
---
---
++
other
proteins
+++
---
---
+++
+/-
---
---
++
10-21
Page 7