Blood Group Antigens Flashcards
Natural Abs
“isoantibodies”
Antibodies to blood group antigens
- preformed Abs w/ no prior exposure/not expressed
- usually low affinity, IgM Abs.
- NOT common in domestic animals
Blood Group Antigen characteristics
- membrane antigens
- usually polysaccharaides
- complex inheritance
- multiple systems in ea. species
Canine Blood Group Most Important Ag.
DEA 1.1
What is DEA 1.1 the most important for?
it is most important for transfusion reactions.
How many Dog Erythrocytes Antigens (DEA) are there?
8 systems. DEA is the most important one
DEA 1.1 frequency
33-45%
DEA 1.1 antigenicity
high
DEA 1.1 tests
in-clinic kit
DEA 1.1 Test involves
a card test with 3 spots for blood drops. there is a control for agglutination
what causes DEA 1.1 card test to not work?
if it agglutinates in the control spot
DEA 1.1+ => DEA 1.1+ reaction
DEA 1.1- => DEA 1.1- reaction
matched reaction!
DEA 1.1- => DEA 1.1+ reaction
reaction unlikely
DEA 1.1+ => DEA 1.1- reaction
1st Reaction: sensitization likely
2nd Reaction: reaction likely!
During the first reaction of DEA 1.1 + => - what does the body do?
start making Abs & blood cells start dying within a week!!
Feline Blood Group Ags
Type A, Type B, Type AB
Type A Feline Blood Group Antigens
genetically dominant type. if one parent is A, then all kids will be As.
common in USA
Type B Feline Blood Group Antigens
Rare in the USA
occur in certain breeds.
Type AB Feline Blood Group Antigens
NOT heterozygotes
RARE!! (<1%)
Type A Feline Blood Gp Ag. Isoantibodies
weak, IgM, IgG, anti-B, low titer
Type B Feline Blood Gp. Ag. Isoantibodies
strong, IgM, anti-A, high titers
Tests for feline blood gp Ags.
in-clinic kits for all types
What does Feline Blood Gp. Ag test look like if patient is AB?
BOTH type A and type B parts agglutinate.
When is there a severe reaction to feline blood transfusions?
when A or AB are given to a B cat
How severe is the reaction when A/AB is given to B cat?
1mL is enough to kill a cat
What happens when B/AB are given to an A cat?
a mild reaction is possible at first.
Blood Transfusion Reaction Mechanisms
- Immune-mediated: type II hypersensitivity
- Non-immune Mediated
Type II Hypersensitivity for Blood Transfusion Reactions
- Complement mediated (ESP if IgM is present)
- Macrophage-mediated: spleen, liver, bn marrow
- Agglutination
- Coagulation System Activation
Coagulation System Activation
- occlude small vessels
- inflammatory reactions also occur systemically
What happens in non-immune mediated blood transfusion reactions?
bad things happen
ie. in blood storage
How do we prevent blood transfusion reactions?
type all donors and all recipients
also cross-match
Major Cross-Matching tests for
Ab in the recipient via the recipient’s serum with donor’s RBCs
Minor Cross-Matching tests for
Abs in the donor via recipients RBCs with donor’s plasma
How do we prevent blood transfusion reactions in dogs specifically?
use DEA 1.1-negative blood for transfusions
