Test Code XMAHG Crossmatch, Antihuman Globulin (AHG)
Useful For
Detection of allo- or autoantibodies directed against donor red blood cell antigens to determine compatibility in the setting of pretransfusion testing
Testing Algorithm
A TS / Type and Screen is required to obtain the specimen necessary for crossmatching. The specimen is good for 3 days, with the day of collection being day zero. The routine testing performed on the type and screen specimen includes: ABO and Rh typing, and antibody screening for unexpected allo antibodies. A positive antibody screen necessitates antibody identification and a determination of the clinical significance of the antibody. A negative antibody screen, with no history of unexpected antibodies, allows the immediate spin crossmatch or electronic crossmatch to be performed if 2 blood types are on record. A positive antibody screen disqualifies the patient for the immediate spin crossmatch and requires the more sensitive antiglobulin phase of testing. The antihuman globulin (AHG) crossmatch is an antiglobulin phase crossmatch that utilizes polyethylene glycol (PEG) as a potentiator.
If donor unit incompatibility is detected, then antibody identification may be performed.
The following tests may also be ordered and performed as part of antibody identification if donor incompatibility is detected: patient/donor antigen typing, direct Coombs IgG, elution, and adsorptions.
Method Name
Antiglobulin Phase Crossmatch
Reporting Name
CrossmatchSpecimen Type
Whole Blood EDTASpecimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole Blood EDTA |
Reject Due To
Gross hemolysis | Reject |
Reference Values
Compatible/Negative
Incompatible/positive, antibody identification will be performed.
Performing Laboratory
MCHS- MankatoTest Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
86920-Crossmatch (IS)
86922-Crossmatch (AHG)
86870-Antibody identification (if appropriate)
86880-Antiglobulin, Direct (if appropriate)
86905-Each red cell antigen typing (if appropriate)
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
XMAHG | Crossmatch | 38167-3 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
XMAHG | Crossmatch | 38167-3 |
Day(s) Performed
Monday through Sunday