Anti-LW Confused with Anti-D: A Case Transfused RhD-positive RBCs and Literature Review

Background: Anti-LW is rarely identified, and it is known to have little clinical importance. However, it is often difficult to differentiate anti-LW from anti-D. Methods: Here, we report a case where anti-LW was identified for pre-transfusion testing in a patient suspected of having lymphoma. Results: His blood group was O RhD-positive. Anti-D specificity, weak pan-reactivity and 2+ reactivity in auto control were shown as a result of antibody identification. The reactions became weaker with DTT-treated RBCs, which confirmed the specificity of an anti-LW. The patient received 8 units of O RhD-positive pRBC before dis-charge without any transfusion reaction. Conclusions: In conclusion, anti-LWs may show mimicking specificity of anti-D for antibody identification testing, but their clinical significance is completely different. Therefore, their prompt identification is important.