1. Cross-matching as part of Pre transfusion compatibility
Dr Md Shah Jalalur Rahman Shahi, SHO
Dr Tanvi Tajmerin, SHO
Department of Laboratory Medicine
United Hospital Limited
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2. Aims
To understand the principle of cross-matching procedure and significance of cross-matching test
To understand the procedure of cross-matching in special circumstances
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3. Purpose Selection of safest blood components for transfusion
With acceptable donor’s red cell survival rates
Without destruction of recipient’s red cells
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4. Importance of Cross-Matching
Routine blood grouping involves only ABO and Rh
Other clinically significant blood group systems not matched routinely
Though, antibodies to minor antigens are of rare occurrence, they can cause transfusion reactions
Cross matching between patient’s serum and donor’s cells will detect antibodies to other blood groups, if present.
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5. History
Rhesus Grouping
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7. Types Major Cross-match: Recipient serum + donor red cells
Minor Cross-match:
Recipient red cells + donor serum
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8. Types contd…
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9. Types contd…
Minor crossmatch: Test donor serum with recipient’s red cells to detect antibodies in donor plasma
Crossmatching can be performed using conventional test tubes or by using newer technologies such as
Column Agglutination Technology
Solid Phase Technology
Electro Magnetic (EM) Technology
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10. Phases Three phases: Saline phase at Room temperatures
Saline phase at 370C temperatures
Anti Human Globulin
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11. Equipment and Reagents
12 *75 test tubes
0.9% saline
Centrifuge
Plastic transfer pipettes
Scissors or segment opening devices
Agglutination mirror
Microscope
370 dry heat incubator
Anti-Human Globulin (Polyclonal IgG/Monoclonal C3d)
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12. Immediate Spin Technique (IST)
2 drops
Patient serum
Patient serum
22oC
Immediate centrifuge
IST also called as Saline Cross Match detects only IgM antibodies reacting at RT such as ABO antibodies.
Clinically significant antibodies such as anti-D will not be detected by IST.
Take 2 drops of patient serum in a clean test tube to which add 1 drop of 5% suspension of donor red cells. Centrifuge at 1000 RPM for one min and look for agglutination
Take 2 drops of patient serum in a clean test tube to which add 1 drop of 5% suspension of donor red cells.
Centrifuge at 1000 RPM for one min and look for agglutination
ABO incompatibility
1 drop, 5%
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Donor RBC

13. Serologic Crossmatch Procedure
Steps
Label the tube with the donor number
Dilute with saline to 2-5% cell suspension
Label a second tube with the donor number and the recipient’s name or initials
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14. Serologic Crossmatch Procedure contd…
Steps
Place 2 drops of the recipient’s plasma or serum into this tube and add 1 drop of donor RBC suspension
Mix and centrifuge each tube for seconds on high speed (3500 rpm)
Examine the supernatant for hemolysis. Resuspend the cells gently and examine for agglutination. Record results on the appropriate worksheet
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15. False Reaction
False reaction may be seen in the presence of other conditions.
In patient with hyperimmune ABO Abs,
When the procedure is not performed correctly (delayed in centrifugation or reading) when rouleauex is observed
When infant’s specimens are tested
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16. Antiglobulin Cross-match (AGXM) procedure
This cross-match should be performed regularly. But this is mandatory in the following situations
If the current antibody screen is positive
There is a history of clinically significant antibodies
In UHL lab we use both Polyclonal IgG and Monoclonal C3d
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17. Technical factors
Donor red blood cells must be obtained from a sealed segment of tubing integral with the container
The cells used for crossmatching may be saline-washed
A 3% to 5% cell suspension is usually recommended
The supernatant must be examined for hemolysis against a white background before resuspending the cetrifuged cells
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18. Technical factors contd….
An optical aid such as a magnifying lens, mirror, or microscope is advised for the reading of agglutination
Hemolysis or agglutination at any stage of the crossmatch indicate an imcompatibility
The person performing the test should be familiar with incubation, centriguation, antiglobulin test
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19. Technical factors contd….
The person performing the test should also be familiar with sources of error, reading of hemolysis, and agglutination
All test should be labeled before use with unit and recipient identification
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20. Cross-matching in emergencies
As the complete cross-matching process takes approximately 1 hour, blood transfusion is started after the blood grouping and cross-matching should be done concurrently.
If any incompatibility is found, then treating physicians should be informed to stop transfusion immediately
It is thought that this lifesaving measure is of more benefit than any risk of an antibody-mediated transfusion reaction.
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23. Advanced methods
Crossmatching can be performed using conventional test tubes or by using newer technologies such as
Column Agglutination Technology
Solid Phase Technology
Electro Magnetic (EM) Technology
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24. Advanced methods
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25. Thank all for your patience
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