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1084 Cross-Match and Blood Typing

Cross-Match and Blood Typing
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occurring antibodies to AB and Mik RBC
Difficulty level: ♦♦
antigens; an AB mismatch can be lethal patients could mount an immune response
against strongly positive DEA 1+ blood.
Synonyms to a type B recipient. • Feline blood-typing kits may not detect type
• Blood typing determines presence or absence ○ AB blood typing cannot detect Mik-related AB cats.
of antigens on the red blood cell (RBC) incompatibilities. • Cats with feline leukemia virus–related anemia
membrane. Clinically, blood group DEA 1 (p. 329) may present discordant blood typing
in dogs and the AB system in cats are most Equipment, Anesthesia results depending on the technique used.
important. Blood typing:
• Major cross-match evaluates for antibodies • In-house canine DEA 1 and feline AB Procedure
in the recipient’s plasma against the donor’s system blood-typing kits (Alvedia Quick • Blood typing: commercially available blood-
RBCs and has greatest clinical significance. Test, others) typing kits (see package inserts)
• Minor cross-match evaluates for antibodies ○ Blood donor animals can be typed with • Cross-match: gel-based major and minor
in the donor’s plasma against the recipient’s a mail-out test along with other donor cross-match test kits are commercialized for
RBCs. screening tests. in-practice use (see figure), and may decrease
• Approximately ≥ 0.4 mL EDTA-anticoag- the subjectivity of interpreting results (see
Overview and Goal ulated (lavender-top tube) whole blood package inserts).
Cross-matching and/or blood typing eliminates Cross-match:
most immunologic transfusion reactions • 1-2 mL EDTA-anticoagulated blood from STANDARD CROSS-MATCH
(p. 989). recipient and donor (or cross-match segments (MAJOR AND MINOR)
from units of blood) Step 1:
Indications • Tabletop centrifuge • Collect 1-2 mL of donor blood in an EDTA
• Blood typing: perform before administering • 3-mL test tubes (or red-top tubes) tube, or use an equivalent 1-2 mL of cross-
a blood transfusion (p. 1169) on all donors • 0.9% saline match segments from desired unit of blood.
and recipients; minimizes sensitization and • Disposable pipettes or 1-mL syringes • Collect 1-2 mL of recipient blood in an
avoids hemolytic transfusion reactions • Test tube rack EDTA tube.
• Cross-match: performed before whole blood • Centrifuge donor and recipient blood in
or packed RBC transfusions on all cats and Anticipated Time separate labeled tubes for 5 minutes (1000 g).
on dogs that received a transfusion > 4 days • Blood typing: 2-5 minutes • Remove plasma using a pipette, and save
previously (even if blood typed) or have an • Major and minor cross-match: 30-40 minutes in separate labeled tubes for later use (use
unknown transfusion history different pipettes for donor and recipient).
○ First-time canine transfusions are consid- Preparation: Important • Wash remaining packed RBCs three times
ered safe without prior cross-matching; Checkpoints by filling tubes with 0.9% saline, gently
dogs do not possess clinically significant • Ensure proper storage and check expiration resuspending, centrifuging (1000 g) for 5
naturally occurring antibodies. Although dates. minutes, and decanting off the saline (discard
mild immunologic incompatibilities have • Blood type or cross-match EDTA blood the saline).
been documented in first-time transfusion samples within 2-3 days of collection; the • After a third wash, add 0.2 mL of washed
recipients, their clinical importance needs physical integrity of RBCs is essential for packed RBCs from the donor red-top tube
further investigation. correct results. to 4.8 mL of 0.9% saline (in a separate
○ Pregnancy does not sensitize dogs to RBC • Breed and geographic prevalence of blood tube), and gently mix to obtain a 3%-5%
antigens. Dogs that have whelped can be types for dogs and cats vary. RBC solution. Make a similar 3%-5% RBC
used as blood donors and can receive a solution with the washed recipient RBCs.
first transfusion without a cross-match Possible Complications and Step 2:
provided they are properly blood typed. Common Errors to Avoid In separate test tubes:
○ Based on flow cytometry techniques, • Dogs or cats that have autoagglutination • Mix 2 drops of recipient plasma and 1
previously typed DEA 1.2-positive (DEA (e.g., immune-mediated hemolytic anemia drop of donor RBC suspension (major
1.2+) dogs appear to be DEA 1+ with [p. 60]) cannot be accurately blood typed cross-match).
weak antigenic expression. using blood-typing cards based on agglutina- • Mix 2 drops of donor plasma and 1 drop
○ A high percentage of Dobermans, Dalma- tion reaction (false-positive) and will most of recipient RBC suspension (minor
tians, and possibly shih tzus are negative likely appear incompatible on cross-match. cross-match).
for the Dal blood type (Dal−), and most • A patient cannot be accurately blood typed • Mix 2 drops of recipient plasma and 1 drop
of the canine population is Dal positive after recent blood transfusion using in-house of recipient RBC suspension (autocontrol).
(Dal+), including blood donors. Consider blood-typing kits. • Incubate at 37°C (ideally, but room tem-
testing above breeds for Dal or performing • Severely anemic cats or dogs (<10% perature is acceptable) for 15-20 minutes.
cross-match because previously sensitized hematocrit) may not show agglutination • Centrifuge for 30 seconds.
Dal− dogs may develop acute or delayed with blood-typing cards (prozone effect). • Observe the plasma for hemolysis. Gently
hemolytic reactions, and compatible blood Centrifuge sample, and remove plasma to resuspend the RBC button by tapping the
may be difficult to find. concentrate RBCs before adding a drop to tube, and examine for agglutination.
○ New canine blood types (Kai 1 and Kai the test card. • Hemolysis or agglutination indicates incom-
2) have been identified, but their clinical • Any weakly to moderately positive DEA 1+ patibility.
relevance is unknown. dog should be considered a DEA 1+ blood
○ Blood typing and cross-matching are donor. For transfusion purposes, transfuse Postprocedure
recommended for all cats, even with first weakly positive DEA 1+ recipients with DEA • Administer type-specific blood to the patient.
transfusion, because cats have naturally 1− blood because it remains unknown if such DEA 1+ dogs can receive DEA 1+ or DEA

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