Background: The Wra blood group antigen is a low-frequency antigen. Antibody screening sets used in pretransfusion laboratory investigations usually do not contain a Wr(a+) cell. If subsequent cross-matching is performed without indirect antiglobulin test (IAT), Wra antibodies reacting with donor red blood cells (RBCs) will be missed. For reasonable economic and time-saving arguments the risk of missing the detection of a potential clinically relevant antibody is worldwide accepted. Case Report: A 66-year-old women with a negative antibody screen rapidly deteriorated after she received two units of RBCs for symptomatic anemia after hip surgery. Diagnosis of a transfusion reaction was obscured by pre-existing and nonspecific symptoms. Laboratory investigation indicated acute hemolysis. Cross-matching in IAT was positive for the first unit, and an extended antibody identification panel showed reactivity with Wr(a+) cells. The patient did not respond to supportive therapy and died within 48 h after the start of transfusion. Conclusion: This dramatic case provides further evidence on the clinical relevance of Wra blood group antibodies. In addition, it underlines the clinical importance of risk awareness in the blood transfusion chain and the possible complexity in relation to patient monitoring in daily transfusion practice.

中文翻译：

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抗 Wra 引起的致命急性溶血性输血反应

背景：Wra 血型抗原是一种低频抗原。用于输血前实验室研究的抗体筛选组通常不包含 Wr(a+) 细胞。如果在没有间接抗球蛋白测试 (IAT) 的情况下进行后续交叉匹配，将错过与供体红细胞 (RBC) 反应的 Wra 抗体。对于合理的经济和节省时间的论点，错过检测潜在临床相关抗体的风险是全世界公认的。病例报告：一名抗体筛查阴性的 66 岁女性在髋关节手术后因症状性贫血接受了两个单位的红细胞后病情迅速恶化。输血反应的诊断被预先存在的和非特异性症状所掩盖。实验室检查提示急性溶血。IAT 中的交叉匹配对第一个单元是积极的，扩展的抗体鉴定组显示与 Wr(a+) 细胞的反应性。患者对支持治疗无反应，在开始输血后 48 小时内死亡。结论：这个戏剧性的案例为 Wra 血型抗体的临床相关性提供了进一步的证据。此外，它强调了输血链中风险意识的临床重要性以及与日常输血实践中患者监测相关的可能复杂性。