Selleng Kathleen, Jenichen Gregor, Denker Kathrin, Selleng Sixten, Müllejans Bernd, Greinacher Andreas
Department of Immunology and Transfusion Medicine, University Medicine Greifswald, Germany.
Department of Anesthesiology, University Medicine Greifswald, Germany.
Lancet Haematol. 2017 May;4(5):e218-e224. doi: 10.1016/S2352-3026(17)30051-0. Epub 2017 Apr 4.
Emergency patients with unknown blood type usually receive O Rhesus D negative (RhD-) red blood cell concentrates until their blood group is determined to prevent RhD+ related adverse transfusion reactions. As 85% of individuals are RhD+, this consumption of O RhD- red blood cell concentrates contributes to shortages of O RhD- red blood cell concentrates, sometimes forcing transfusion of known RhD- patients with RhD+ red blood cell concentrates. Here we report the outcome of this transfusion policy transfusing all emergency patients with unknown blood type with O RhD+ red blood cell concentrates.
In this prospective single-centre observational study done between Jan 1, 2001, and Dec 31, 2015, we assessed all consecutive RhD- patients at the University Medicine Greifswald who received RhD+ red blood cell concentrates (emergency patients with unknown blood type; and RhD- patients receiving RhD+ red blood cell concentrates during RhD- red blood cell concentrate shortages). No patients were excluded. The primary endpoint was anti-D allo-immunisation at 2 months follow-up or later. Patients were followed up and tested for immunisation against red blood cell antigens using the direct antiglobulin test and an antibody screen every 3-5 days for 4 weeks or until death, or hospital discharge. Surviving patients were screened for development of anti-D antibodies for up to 12 months (at the predefined timepoints 2, 3, 6, and 12 months) after RhD+ red blood cell transfusion.
437 emergency patients, of whom 85 (20%) were RhD-, received 2836 RhD+ red blood cell concentrates. The overall risk of inducing anti-D antibodies (in all 437 recipients) was 17 (4%, 95% CI 2·44-6·14) of 437 (assuming all patients lost to follow-up developed anti-D allo-immunisation). During this period, 110 known RhD- patients received RhD+ red blood cell concentrates during RhD- red blood cell concentrate shortages. Of these, 29 (26%; 95% CI 19·0-35·3) developed anti-D allo-immunisation (assuming all patients lost to follow-up developed anti-D), which was significantly higher than in the emergency patients with unknown blood type (p<0·0001).
Transfusing emergency patients with unknown blood type with O RhD+ red blood cell concentrates has a low risk of inducing anti-D antibodies (3-6%), but saves more than 10% of the total O RhD- red blood cell concentrate demand, thereby reducing shortage of O RhD- red blood cell concentrates, the need to transfuse known RhD-patients with RhD+ red blood cell concentrates, and thus the overall risk to induce anti-D allo-immunisation in the population. These findings should be considered for transfusion guidelines.
University Medicine Greifswald.
血型未知的急诊患者通常会输注O型RhD阴性（RhD-）红细胞浓缩液，直到确定其血型，以预防与RhD阳性（RhD+）相关的不良输血反应。由于85%的个体为RhD+，这种O型RhD-红细胞浓缩液的消耗导致了O型RhD-红细胞浓缩液的短缺，有时迫使已知RhD-的患者输注RhD+红细胞浓缩液。在此，我们报告了对所有血型未知的急诊患者输注O型RhD+红细胞浓缩液这一输血政策的结果。
在这项于2001年1月1日至2015年12月31日进行的前瞻性单中心观察性研究中，我们评估了格赖夫斯瓦尔德大学医学中心所有连续接受RhD+红细胞浓缩液的RhD-患者（血型未知的急诊患者；以及在RhD-红细胞浓缩液短缺期间接受RhD+红细胞浓缩液的RhD-患者）。没有患者被排除。主要终点是在2个月随访或更晚时的抗-D同种免疫。对患者进行随访，并每3 - 5天使用直接抗球蛋白试验和抗体筛查检测红细胞抗原免疫情况，持续4周或直至死亡或出院。存活患者在输注RhD+红细胞后长达12个月（在预先定义的2、3、6和12个月时间点）进行抗-D抗体产生情况筛查。
437例急诊患者中，85例（20%）为RhD-，共接受了2836单位RhD+红细胞浓缩液。诱导产生抗-D抗体的总体风险（在所有437例接受者中）为437例中的17例（4%，95%CI 2.44 - 6.14）（假设所有失访患者均产生了抗-D同种免疫）。在此期间，110例已知RhD-的患者在RhD-红细胞浓缩液短缺期间接受了RhD+红细胞浓缩液。其中，29例（26%；95%CI 19.0 - 35.3）产生了抗-D同种免疫（假设所有失访患者均产生了抗-D），这显著高于血型未知的急诊患者（p<0.0001）。
对血型未知的急诊患者输注O型RhD+红细胞浓缩液诱导产生抗-D抗体的风险较低（3 - 6%），但可节省超过10%的O型RhD-红细胞浓缩液总需求量，从而减少O型RhD-红细胞浓缩液的短缺，减少已知RhD-患者输注RhD+红细胞浓缩液的需求，进而降低人群中诱导产生抗-D同种免疫的总体风险。这些发现应在输血指南中予以考虑。
格赖夫斯瓦尔德大学医学中心。
