Compatibility Testing

Question 1

Testing of the Donor sample

Answer 1

• ABO grouping
• Rhgrouping
• weak D, Du
• TTI’s

Question 2

Identify what type of blood typing:
- Sample Red Cells and Typing sera
- Sample Antigen detected

Answer 2

Forward typing

Question 2

Testing for the Patient sample

Answer 2

• ABO grouping
• Rh grouping
• Unexpected antibodies

Question 2

Identify what type of blood typing:
- Sample serum/plasma and Known Red Cells
- sample antibody detected

Answer 2

Reverse typing

Question 3

More sensitive method when it comes to blood typing

Answer 3

tube method

Question 4

Detect as many clinically significant antibodies, minimize detection of nuisance antibodies, and prompt delivery of blood to patient

Answer 4

Antibody screening

Question 4

Determines ABO and Rh grouping of both patient and donor
blood

Answer 4

ABO Grouping

Question 5

Reactive at 37°C and/or in the AHG test and known to cause transfusion reaction or unacceptably short
survival of transfused red cells

Answer 5

clinically significant antibodies

Question 6

Antibody Screening is performed using selected _______ red cells that are known to
carry optimal representation of important blood group
antigens.

Answer 6

group O

Question 7

Phase 1 of Antibody Screening

Answer 7

Immediate spin

Question 8

May be omitted but it may also give additional information as to whether the reaction is due to an IgM antibody instead of IgG or complement
activation.

Answer 8

Immediate spin

Question 9

Usually considered “nuisance” antibodies

Answer 9

IgM antibodies

Question 10

In performing Immediate Spin, 3 tubes are needed that contains

Answer 10

• Recipient serum plus saline suspension Screening Cell I
• Screening Cell II, and
• Recipient’s own cells for the auto control

Question 11

Phase 2 of Antibody Screening

Answer 11

37C Incubation

Question 12

This phase is required since IgG clinically-significant antibodies are warm-acting antibodies

Answer 12

37C phase

Question 13

37C Incubation can be added with enhancement media such as

Answer 13

LISSor albumin

Question 14

Composed of NaCl, glycine and phosphate buffer along sodium preservative.

Answer 14

LISS or Low Ionic Strength Solution

Question 15

This solution
speeds up antigen-antibody reaction but unfortunately enhances “nuisance” antibodies, so add after immediate spin
step

Answer 15

LISS or Low Ionic Strength Solution

Question 16

This is added to 37C incubation to lower zeta potential so cells can agglutinate without Coombs step and may detect Rh antibodies

Answer 16

Albumin

Question 17

Whether adding an enhancement media or not we must do _______, but we do not need to read at this step. We-can proceed directly to Coombs (AHG or AGT) phase.

Answer 17

37C incubation

Question 18

Phase 3 of Antibody Screening

Answer 18

Coombs phase (AHG or AGT)

Question 19

This phase is required since a number of these clinically significant antibodies may only show up at
this phase

Answer 19

Coombs phase (AHG or AGT)

Question 20

Adding this in Phase 3 to all negative results to confirm negative reactions

Answer 20

Coombs Control Cells

Question 21

Always Potentially Clinically Significant antibodies

Answer 21

• ABO
• Rh
• Duffy
• Kell
• SsU
• Kidd

Question 22

Sometimes clinically significant antibodies

Answer 22

- Lea - Lutheran (Lu a, Lu b) - MN - Cartwright (Yta) - P1

Question 23

Rarely clinically significant antibodies

Answer 23

- Leb - Xga - Chido/Rodgers (Ch a/Rga) - HTLA - Sda

Question 24

Note: Crossmatching **is only a part** of compatibility testing

Question 25

Mixing the patient’s serum with donor’s red cells

Answer 25

Major Crossmatching

Question 26

Mixing patient’s red cells with donor’s plasma

Answer 26

Minor Crossmatching

Question 27

Completely eliminated from most blood banks –antibody screening beforehand

Answer 27

Minor crossmatching

Question 28

Methods of Major Crossmatch Tests

Answer 28

- Intermediate Spin Crossmatch - Antiglobulin Crossmatch - Antiglobulin Crossmatch

Question 29

Mixing patient’s serum with donor’s red cells and centrifuge immediately

Answer 29

Intermediate Spin Crossmatch

Question 30

Using this eliminate some false-positive reactions, improving sensitivity

Answer 30

EDTA

Question 30

False Reaction in Intermediate Spin Crossmatch is seen in:

Answer 30

1. presence of other immediate spin-reactive antibodies (e.g. autoanti-I) 2. patients with hyperimmune ABO antibodies 3. procedure not performed correctly (delay in centrifugation, reading) 4. Infant specimen

Question 31

Begins in the same manner as the immediate spin crossmatch, continues to a 37°C incubation, and finishes with an anti-globulin test

Answer 31

Antiglobulin Crossmatch

Question 32

Methods used to enhance antigen-antibody reactions:

Answer 32

- Albumin - Low ionic strength sol’n (LISS) or Polyethylene glycol (PEG)

Question 33

Added before incubation, this enhances reactivity of some antibodies

Answer 33

Albumin

Question 34

May be added in place of albumin, facilitate complexing of antigens and antibodies

Answer 34

LISS or PEG

Question 35

Rapid and sensitive crossmatch technique. Used in detecting ABO incompatibility accompanied by negative antibody screening on the patient.

Answer 35

Polybrene (P-AHG)

Question 36

Not required, however, in large volume transfusion, _________ using patient red cells and donor plasma is sufficient

Answer 36

immediate spin crossmatch