Department of Medical Biophysics, University of Western Ontario, Ontario, Canada.
Transfusion. 2009 Nov;49(11):2304-10. doi: 10.1111/j.1537-2995.2009.02315.x. Epub 2009 Jul 17.
Ex vivo storage of red blood cells (RBCS) for transfusions is associated with a "storage lesion," which decreases RBC deformability and increases RBC adhesiveness to vascular endothelium. This may impair microcirculatory flow with deleterious effects on oxygen delivery after transfusion. Previous studies have shown that human RBCs adhere to endothelial monolayers in vitro with prolonged storage and is reduced by prestorage leukoreduction (LR). The objective of this study was to determine whether duration of RBC storage and LR influence RBC adhesion in vivo in capillaries.
Rat RBCs were collected and stored in CPDA-1 under standard blood bank conditions. Three RBC products were compared: 1) fresh RBCs, less than 24 hours of storage (n = 6); 2) non leukoreduced (NLR) RBCs stored for 7 days (n = 6); and 3) prestorage LR RBCs stored for 7 days (n = 6). RBCs were labeled with fluorescein isothiocyanate (FITC) 24 hours before transfusion and reinjected in an isovolemic manner into healthy rats. The FITC-labeled RBCs were visualized in the extensor digitorum longus muscle using intravital video microscopy (20 x magnification). The number of RBCs adherent in capillaries was counted 1 hour after transfusion in 10 random fields and the median values were compared with one-way analysis of variance.
Stored RBCs showed increased levels of adherence in capillaries compared to their fresh counterparts (p < 0.05). Prestorage LR decreased RBC adherence to levels equivalent to those of fresh RBCs (p < 0.05 for stored LR vs. stored NLR).
Rat RBCs stored under conditions that closely mimicked clinical transfusion adhere in capillaries. The decreased RBC adherence with LR suggest a direct effect of white blood cells or their byproducts on RBC deformability and/or adhesiveness to microvascular endothelium. Further study will examine the mechanism of adherence and the impact it has on microcirculatory flow and oxygen delivery in the critically ill host.
用于输血的红细胞（RBC）的体外储存与“储存损伤”有关，这会降低 RBC 的变形能力并增加 RBC 与血管内皮的黏附性。这可能会损害微循环血流，对输血后的氧输送产生不利影响。先前的研究表明，在体外，随着储存时间的延长，人类 RBC 会黏附在内皮单层细胞上，而预储存白细胞减少（LR）会减少这种黏附。本研究的目的是确定 RBC 储存时间和 LR 是否会影响体内毛细血管中的 RBC 黏附。
从大鼠中收集 RBC 并在 CPDA-1 中按标准血库条件储存。比较了三种 RBC 产品：1）少于 24 小时储存的新鲜 RBC（n = 6）；2）未进行白细胞减少处理（NLR）的 RBC 储存 7 天（n = 6）；3）预储存 LR 的 RBC 储存 7 天（n = 6）。在输血前 24 小时用荧光素异硫氰酸酯（FITC）标记 RBC，并以等容方式将其重新注入健康大鼠体内。使用活体视频显微镜（20x 放大倍数）在伸趾长肌中观察 FITC 标记的 RBC。在输血后 1 小时，在 10 个随机视野中计数黏附在毛细血管中的 RBC 数量，并使用单因素方差分析比较中位数。
与新鲜 RBC 相比，储存的 RBC 在毛细血管中的黏附水平升高（p < 0.05）。预储存 LR 降低了 RBC 的黏附水平，使其达到与新鲜 RBC 相当的水平（储存 LR 与储存 NLR 相比，p < 0.05）。
在模拟临床输血条件下储存的大鼠 RBC 会黏附在毛细血管中。LR 降低 RBC 黏附表明白细胞或其产物对 RBC 变形能力和/或与微血管内皮的黏附性有直接影响。进一步的研究将检查黏附的机制及其对危重病宿主微循环血流和氧输送的影响。
