DETECTION OF IRREGULAR ANTIBODIES BY LISS-IAT DURING BLOOD TRANSFUSION THERAPY: TWO CASE REPORTS

Abstract

We report two cases in which the irregular antibody Rh system was produced or reactivated despite transfusion of a red blood cell (RBC-LR) preparation of the same Rh blood type as that of the patient during blood transfusion therapy for hematologic disorders. Case 1 was negative upon testing for irregular antibodies prior to blood transfusion, and anti-E positivity was found using the enzyme method alone after RBC-LR blood transfusion. Although the patient was tranfused with E- and c-negative RBC-LR, an indirect antiglobulin test after transfusion of platelet preparation (PC-LR) detected anti-E positivity. In Case 2, anti-E positivity was found in the test for irregular antibodies before blood transfusion. The patient was tranfused with E- and c-negative RBC-LR. Although the patient subsequently became negative for anti-E, antibody positivity was detected again after PC-LR transfusion, whereby anti-c was also positive. Very small amounts of E- and c-positive red blood cells were present in the PC-LR. The factor responsible for the irregular antibody-producing or -activating effect was unclear in Case 1. Therefore, further investigation into the cause is needed by accumulating similar cases in the future. For Case 2, we speculate that the very small amounts of red blood cells in the PC-LR may have contributed to irregular antibody production. In addition to RBC-LR, these cases suggest that it is important to re-test patients for irregular antibodies even after PC-LR transfusion. In addition, at our hospital we provide an "irregular antibody card" to patients with clinically important antibody irregularities and encourage the sharing of patient information with other facilities.