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 27/08/2015

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 27/08/2015

Purpose Selection of safest blood components for transfusion With acceptable donor’s red cell survival rates Without destruction of recipient’s red cells 27/08/2015

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. 27/08/2015

History Rhesus Grouping 27/08/2015

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Types Major Cross-match: Recipient serum + donor red cells Minor Cross-match: Recipient red cells + donor serum 27/08/2015

Types contd… 27/08/2015

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 27/08/2015

Phases Three phases: Saline phase at Room temperatures Saline phase at 370C temperatures Anti Human Globulin 27/08/2015

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) 27/08/2015

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% 27/08/2015 Donor RBC

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 27/08/2015

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 15-20 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 27/08/2015

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 27/08/2015

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 27/08/2015

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 27/08/2015

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 27/08/2015

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 27/08/2015

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. 27/08/2015

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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 27/08/2015

Advanced methods 27/08/2015

Thank all for your patience 27/08/2015

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