Two cases of anti-LW in which DTT treatment ID-DiaCell was useful for confirming false positive reactions with stored anti-CD38 antibody drugs

Abstract

Introduction: At our hospital, we prepare and store dithiothreitol (DTT)-treated irregular antibody screening (SC) blood cells for each lot change as confirmation of false-positive reactions to anti-CD38 antibody drug administration for irregular antibody testing. DTT-treated erythrocytes are useful to confirm the chemical properties of irregular antibodies. Here, we describe two cases in which anti-Landsteiner–Wiener (LW) was suspected in an irregular antibody test, and DTT-treated SC erythrocytes were useful for confirmation. Case 1 is a woman in her 70s who is positive for type B RhD and negative for SC. After 1 month, two red blood cell transfusion units were requested because of low Hb levels. Irregular antibody SC was positive, and the identification test showed an anti-D-like reaction. The irregular antibody SC test with DTT-treated SC erythrocytes was negative and anti-LW. Six red blood cell units were transfused and no adverse reactions occurred. Case 2 is a woman in her 90s with myelodysplastic syndrome who is positive for RhDO and irregular antibodies. The identification test showed an anti-D-like reaction, which was negative in the irregular antibody test with DTT-treated SC erythrocytes, and was anti-LW. Sixteen red blood cell units were transfused and no adverse reactions occurred. Discussion: Anti-LW is not a clinically significant antibody but has cross-match incompatibility. Moreover, RhD-negative erythrocytes with less LW antigen should be used because reactive confirmation by DTT-treated erythrocytes is important for differentiating anti-LW from anti-D-like autoantibodies. DTT-treated erythrocytes used to confirm false-positive reactions to anti-CD38 antibody drugs were useful for detecting anti-LW.