Examples of Incompatible Crossmatches Immunohematology Review 467
REACTIONS POSSIBLE CAUSE* RESOLUTION
Neg ab screen, incompatible IS xmatch1 ab screening cell & 1 donor pos in AHGAb screening cells & all donors except 1 neg
at 37°C & in AHG. 1 donor pos in AHG onlyAb screening cells, donors, & autocontrol
pos in AHGAb screening cells, donors, & autocontrol
pos at 37°C, neg in AHG*Other causes are possible.
Retype donor & recipient. Xmatch with ABO-compatible donor.Identify ab. Xmatch units neg for corresponding ag.Perform DAT on unit. If pos, return to collecting facility.Best not to tf. If unavoidable, find “least incompatible” unit.Saline replacement technique.ABO incompatibilityAlloantibodyPositive DAT on donorWarm autoantibodyRouleaux