Limitations of the crossmatch for detection of incompatibility between A2B red blood cells and B patient sera.

A recent evaluation of the immediate-spin crossmatch has revealed limitations when used for the detection of ABO incompatibilities in tests between group B patient sera and group A2B donor red blood cells. Presented with the option of deleting the anti-globulin crossmatch, the study reported here was conducted to determine whether the anti-globulin crossmatch would detect the ABO incompatibilities missed by the immediate spin. Results of 1,000 crossmatches between group B patient sera and group A2B red blood cells showed that the anti-globulin phase was capable of detecting a higher percentage of incompatibilities than the immediate-spin procedure, 79.4-86.8% versus 40-64.4%, respectively, depending on the enhancement used. Although anti-globulin testing did detect a substantially higher number of incompatibilities, are the increased cost of reagents and technologists' time used in performing the anti-globulin crossmatch justified for the detection of ABO incompatibilities? Due to limitations observed with the anti-globulin test in addition to budgetary and fiscal constraints, retention of the anti-globulin testing purely for ABO compatibility is not warranted.

Limitations of the immediate spin crossmatch when used for detecting ABO incompatibility.

In the eleventh edition of the AABB's Standards for Blood Banks and Transfusion Services the requirement for an antiglobulin crossmatch was deleted if no clinically significant unexpected antibodies are detected in recipient serum testing and if there is no history of detection of such antibodies. Test methods that demonstrate ABO incompatibility remain a requirement; however, the means to accomplish this may prove controversial. The immediate spin crossmatch has been used for the purpose of detecting ABO incompatibility by many workers. Nonetheless, limitations of this technique became apparent in tests between A2B donor red cells and group B patient sera. The results of 204 of 531 immediate spin crossmatches, between these two blood groups, were found to be negative.