Anti-KEL1 antigen (also referred to as anti-Kell, or anti-K) alloimmunisation is the second most common cause of severe haemolytic disease of the fetus and newborn, after anti-rhesus D antigen, and can cause substantial fetal morbidity and mortality. Both fetal erythropoietic suppression and haemolysis contribute to anaemia. Typically, once a clinically significant alloantibody is identified during pregnancy, antibody titration is performed as a screening test to predict the risk of anaemia and the need for maternal–fetal medicine referral. The titre is a semiquantitative laboratory method based on the underlying principle that increased maternal antibody concentrations are associated with an increased risk of fetal anaemia. Because some studies report that anti-K alloantibodies can lead to severe anaemia even at a low antibody titration, guidelines are inconsistent with respect to the role of titration testing. Some experts recommend maternal–fetal medicine referral and middle cerebral artery Doppler ultrasound without titration testing or with the use of a very low cutoff titre. This Viewpoint evaluates management for pregnancies affected by anti-K alloantibodies and highlights literature regarding the predictive value of anti-K titration testing.

中文翻译：

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使用抗 K 同种抗体管理妊娠和抗 K 滴定试验的预测价值


抗 KEL1 抗原（也称为抗 Kell 或抗 K）同种异体免疫是胎儿和新生儿严重溶血性疾病的第二大常见原因，仅次于抗恒河猴 D 抗原，可导致大量胎儿并发症和死亡。胎儿红细胞生成抑制和溶血都会导致贫血。通常，一旦在妊娠期间发现具有临床意义的同种抗体，就会进行抗体滴定作为筛查试验，以预测贫血的风险和是否需要母胎医学转诊。滴度测定是一种半定量实验室方法，其基本原理是母体抗体浓度升高与胎儿贫血风险增加有关。由于一些研究报告称，即使在抗体滴定度较低时，抗 K 同种抗体也会导致严重贫血，因此指南对滴定试验的作用并不一致。一些专家建议母胎医学转诊和大脑中动脉多普勒超声检查，无需滴定测试或使用非常低的临界滴度。本观点评估了受抗 K 同种抗体影响的妊娠的管理，并重点介绍了有关抗 K 滴定试验预测价值的文献。