Introduction: Damage to a cell and the loss of integrity of its cell membrane leads to the release of endogenous immunogenic molecules, which together are classified as “damage-associated molecular patterns” (DAMPs). Cell-free DNA (cf-DNA) released from nucleosomes may serve as a procoagulant cofactor and may be an important mediator of immunomodulatory and proinflammatory effects associated with blood transfusion. Objectives: To assess the levels of cf-DNA in supernatants of stored red cell components and the effect of leukoreduction and gamma irradiation on the release of cf-DNA during storage. Methods: This is a prospective cohort study on 99 stored red cell components, randomly divided into three groups – buffy coat (BC)-depleted, leuko-filtered (LP), and irradiated (IR) packed red blood cells. Red cell supernatants were drawn over a period of 21 days at three different time points (day 0, 7, and 21) from the study units. cf-DNA extraction was done and quantified by a bench top fluorometer. Change in cf-DNA content, rate of change (μg/day), and percent change were estimated and compared across different groups. Results: cf-DNA content increased (p = 0.000) with storage duration in the BC (median = 238.66 μg, interquartile range [IQR] = 168.42 on day 21 vs. median = 9.44 μg, IQR = 5.23 on day 0) and IR groups (p = 0.000) (median = 245.55 μg, IQR = 253.88 on day 21 vs. median = 7.07 μg, IQR = 13.58 on day 0), while there was a decreasing trend (p = 0.032) in the LP group (median = 4.55 μg, IQR = 10.73 on day 21 vs. median = 8.66 μg, IQR = 6.56 on day 0). The median rate of change in cf-DNA content (11.13 μg/day) and percent change in cf-DNA content (median = 4,106.16%) was highest in the IR group. Conclusions: Stored red cell components contain significant amount of cf-DNA. Release of cf-DNA is further aggravated by irradiation while leukoreduction leads to a decrease in cf-DNA content.

中文翻译：

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评估储存时间、白细胞过滤和伽马射线照射对红细胞成分中游离 DNA 影响的前瞻性队列研究

简介：对细胞的损伤及其细胞膜完整性的丧失导致内源性免疫原性分子的释放，这些分子一起被归类为“损伤相关分子模式”（DAMP）。从核小体释放的游离 DNA (cf-DNA) 可作为促凝血辅因子，并且可能是与输血相关的免疫调节和促炎作用的重要介质。目的：评估储存红细胞成分上清液中 cf-DNA 的水平，以及白细胞减少和伽马射线照射对储存期间 cf-DNA 释放的影响。方法：这是一项针对 99 种储存红细胞成分的前瞻性队列研究，随机分为三组——去除血沉棕黄层 (BC)、滤过白细胞 (LP) 和辐照 (IR) 填充的红细胞。在 21 天的时间里，在三个不同的时间点（第 0、7 和 21 天）从研究单位中抽取红细胞上清液。cf-DNA 提取通过台式荧光计进行和定量。对不同组的 cf-DNA 含量变化、变化率（μg/天）和变化百分比进行了估计和比较。结果： cf-DNA 含量随着 BC 中储存时间的增加（中位数 = 238.66 μg，第 21 天的四分位距 [IQR] = 168.42 而中位数 = 9.44 μg，IQR = 5.23 在第 0 天）和 IR 增加（p = 0.000）组（p = 0.000）（中位数 = 245.55 μg，第 21 天的 IQR = 253.88 vs. 中位数 = 7.07 μg，第 0 天的 IQR = 13.58），而 LP 组（中位数）呈下降趋势（p = 0.032） = 4.55 μg，第 21 天的 IQR = 10.73 与中位数 = 8.66 μg，第 0 天的 IQR = 6.56）。cf-DNA 含量的中位变化率 (11. 13 μg/天）和 cf-DNA 含量的百分比变化（中位数 = 4,106.16%）在 IR 组中最高。结论：储存的红细胞成分含有大量的 cf-DNA。照射会进一步加剧 cf-DNA 的释放，而白细胞减少会导致 cf-DNA 含量降低。