Haematology Department, Hospital General Universitario Gregorio Marañón, Madrid.
Instituto de Investigación Sanitaria Gregorio Marañón, Madrid.
Blood Transfus. 2021 Jul;19(4):292-299. doi: 10.2450/2020.0096-20. Epub 2020 Oct 14.
Red blood cell (RBC) transfusion remains an essential part of sickle cell disease (SCD) management but it can lead to alloimmunisation, with an increased incidence in this population. Prevention is based on RBC antigen phenotype matching, with complete RH and Kell matching being a standard of care.
We performed a retrospective, single-centre study analysing alloimmunisation prevalence and risk factors in a cohort of transfused SCD patients.
Eighty-seven patients (96.5% of paediatric age) received 1,781 RBC units (RBCu). Complete RH and Kell matched RBCu represented a median of 100% among total transfusions per patient. Of the 87 patients, 52 (59.8%) underwent chronic transfusion therapy, whereas 35 (40.2%) were only episodically transfused. Seven patients were alloimmunised (8.4%) and eleven antibodies were detected (alloimmunisation rate: 0.62/100 units transfused). 54.6% of these antibodies corresponded to RH-Kell despite the high accomplishment of the RH-Kell matching transfusion protocol. Alloimmunised patients had a median of 90.9% RH-Kell matched transfusions vs 100% in non-alloimmunised patients, but no statistical differences were observed (p=0.127). Number of transfused RBCu (19 vs 7; p=0.023), number of episodic RBCu (8 vs 2; p=0.006), episodic to chronic RBCu ratio (0.57 vs 0.09; p=0.045), number of vaso-occlusive crises (VOC) (4 vs 2; p=0.011), and autoantibody presence (57.1 vs 0%; p<0.001) were all statistically related to alloimmunisation.
We report a low alloimmunisation prevalence (8.4%) related to a high grade of RH-Kell matching. However, deviation from 100% translates into alloimmunisation, with >50% of alloantibodies corresponding to RH-Kell. Alloimmunisation risk increases with transfusion burden, particularly during acute complications, and in patients with a higher number of VOC, probably reflecting underlying inflammation and disease severity. Further studies will be needed to elucidate additional risk factors and help prevent alloimmunisation in these patients.
红细胞（RBC）输血仍然是镰状细胞病（SCD）管理的重要组成部分，但它会导致同种免疫，这种情况在该人群中的发生率增加。预防措施基于 RBC 抗原表型匹配，完全 RH 和 Kell 匹配是护理标准。
我们进行了一项回顾性单中心研究，分析了输血 SCD 患者队列中的同种免疫发生率和危险因素。
87 名患者（96.5%为儿科年龄）接受了 1781 个 RBC 单位（RBCu）。每位患者的总输血中，完全 RH 和 Kell 匹配的 RBCu 中位数为 100%。在 87 名患者中，52 名（59.8%）接受了慢性输血治疗，而 35 名（40.2%）仅间歇性输血。7 名患者发生同种免疫（8.4%），检测到 11 种抗体（同种免疫率：0.62/100 单位输血）。尽管 RH-Kell 匹配的输血方案完成度很高，但其中 54.6%的抗体对应 RH-Kell。同种免疫患者的中位 RH-Kell 匹配输血率为 90.9%，而非同种免疫患者为 100%，但无统计学差异（p=0.127）。接受的 RBCu 输血次数（19 与 7；p=0.023）、间歇性 RBCu 输血次数（8 与 2；p=0.006）、间歇性与慢性 RBCu 输血比例（0.57 与 0.09；p=0.045）、血管阻塞性危象（VOC）次数（4 与 2；p=0.011）和自身抗体存在（57.1%与 0%；p<0.001）均与同种免疫相关。
我们报告了一种较低的同种免疫发生率（8.4%），与较高水平的 RH-Kell 匹配相关。然而，偏离 100%会导致同种免疫，超过 50%的同种抗体对应 RH-Kell。同种免疫风险随着输血负担的增加而增加，特别是在急性并发症期间，并且在 VOC 次数较多的患者中，这可能反映了潜在的炎症和疾病严重程度。需要进一步的研究来阐明其他危险因素，并帮助预防这些患者的同种免疫。
