CROSSMATCHING TECHNIQUES
CROSSMATCHING TESTING
Cross matching
The AABB and FDA develop the standards for blood banking
According to the AABB Standards:
The crossmatch “shall use methods that demonstrate ABO incompatibility and clinically significant antibodies to red cell antigens and shall include an antiglobulin phase”
Purpose:
- Prevent transfusion reactions
- Increase in vivo survival of red cells
- Double checks for ABO errors
- Another method of detecting antibodies
Types of Cross matching
- Major – routinely performed in labs
- Minor – not required by AABB since 1976
Crossmatches...
MAJOR VS MINOR CROSSMATCHING
Will
Verify donor cell ABO compatibility
Detect most antibodies against donor cells
Will Not
Guarantee normal survival of RBCs
Prevent patient from developing an antibody
Detect all antibodies
Prevent delayed transfusion reactions
Detect ABO/Rh errors
PROCEDURE
Submitted to:
Dr. Atibagos
Sir. Fritz Gonazaga
Submitted by:
Quinn Everette N. Ramirez
Kimberly D. Ramos
Arielle Mae M. Saim
Lara Maica Salem
Joriza Marie Angeline D.R Sanchez
MICO 43
METHOD FOR MAJOR CROSSMATCH
Computer Crossmatch
The electronic crossmatch according to the AABB, the following must be fulfilled:
- Critical elements of the information system have been validated on-site.
- No clinically significant antibodies are detected in the current blood sample and there is no record of clinically significant antibodies in the past
ANTIGLOBULIN CROSSMATCH
- The patient's ABO group and Rh type has been done twice and entered in the computer
- The donor ABO/Rh have been confirmed and entered in the computer. The donor unit identification number, component name, and ABO/Rh type must also be entered in the computer
- The computer system will alert the technologist to ABO & Rh discrepancies between information on the donor label and results of donor confirmatory testing
The procedure begin in the same manner as the IS cross-match, continues to 37°C incubation and finishes with AHG test.
Method for major cross-match tests
- In IS (the patient’s serum with donor cell are centrifuge immediately) absence of hemolysis or agglutination indicates compatibility.
- False reaction may be seen in the presence of other IS reaction (auto -I). In patient with hyperimmune ABO Abs, when the procedure is not performed correctly (delayed in centrifugation or reading) when rouleauex is observed, or when infant’s specimens are tested.
Method for major cross-match tests
- Cross-match methods can be categorized by the test phase in which the procedure ends.
- Immediate spin (IS) cross-match (Abbreviated
Cross-match)
- When no clinically significant Abs are detected nor are there previous record of such Abs, a serologic test to detect ABO incompatibility is sufficient.