Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada.
Innovation and Portfolio Management, Canadian Blood Services, Edmonton, Alberta, Canada.
Transfusion. 2022 Apr;62(4):751-757. doi: 10.1111/trf.16809. Epub 2022 Jan 30.
Gamma irradiation of red cell concentrates (RCCs) is regularly used to prevent transfusion-associated graft-versus-host disease (TA-GvHD) in at-risk patients. While studies have indicated that irradiated RCCs exhibit increased hemolysis, there have been no efforts to differentiate between free- and microvesicle (MV)-bound hemoglobin (Hb). As an increase in the proportion of free-Hb in irradiated RCCs could alter vascular function, we sought to characterize differences in the state of extracellular Hb based on the timing of irradiation.
Four separate pools of seven CPD/SAGM leukoreduced RCCs were produced and split into four sets of seven identical units. The units from each set were subject to irradiation (25 Gy) at six different points during storage, with one unit serving as a nonirradiated control. All testing was performed immediately following unit expiry on day 43.
The earlier in storage that units were irradiated, the higher the hemolysis and the lower the proportion of MV-bound Hb. Units irradiated earlier in storage (1-8 days post collection) additionally had lower membrane rigidity (K ), lower mean corpuscular Hb concentrations (MCHC), and higher mean corpuscular fragility (MCF). Morphology indices, mean cell volume (MCV), mean corpuscular Hb (MCH), phosphatidylserine (PS) expression, as well as MV production and size did not however differ significantly between groups based on the timing of irradiation.
Our findings indicate that irradiation timing can alter the state of extracellular Hb, with "early" irradiation promoting an increased proportion of cell-free Hb as well as mechanical damage to the RBC membrane.
辐照红细胞浓缩物（RCC）通常用于预防高危患者的输血相关移植物抗宿主病（TA-GvHD）。虽然研究表明辐照 RCC 会增加溶血，但尚未努力区分游离和微泡（MV）结合的血红蛋白（Hb）。由于辐照 RCC 中游离 Hb 比例的增加可能会改变血管功能，我们试图根据辐照时间来区分细胞外 Hb 的状态。
制备了四个 CPD/SAGM 去白细胞 RCC 池，每个池分为七个相同的单位。将每个池的单位分为四组，在储存过程中的六个不同时间点进行辐照（25Gy），其中一个单位作为未辐照对照。所有测试均在第 43 天的单位过期后立即进行。
单位辐照时间越早，溶血越高，MV 结合的 Hb 比例越低。储存早期（采集后 1-8 天）辐照的单位还具有较低的膜刚性（K）、较低的平均红细胞 Hb 浓度（MCHC）和较高的平均红细胞脆性（MCF）。然而，根据辐照时间，各组之间的形态学指数、平均细胞体积（MCV）、平均红细胞 Hb（MCH）、磷脂酰丝氨酸（PS）表达以及 MV 产生和大小没有显著差异。
我们的发现表明辐照时间可以改变细胞外 Hb 的状态，“早期”辐照会增加游离 Hb 的比例，并对 RBC 膜造成机械损伤。
