Wagner S J, Moroff G, Katz A J, Friedman L I
Jerome H. Holland Laboratory for the Biomedical Sciences, American Red Cross Blood Services, Rockville, Maryland, USA.
Transfusion. 1995 Apr;35(4):298-302. doi: 10.1046/j.1537-2995.1995.35495216077.x.
The ability to store pools of platelet concentrates (PCs) for extended periods would provide logistical flexibility. However, reports of severe adverse reactions due to the transfusion of contaminated PCs led to an examination of whether the total bacteria levels after storage of pools containing a deliberately inoculated platelet unit would be significantly different than the levels in paired unpooled concentrates.
A single PC was deliberately inoculated on Day 0 with one of three bacterial species (0.1-8.0 colony-forming units/mL). On Day 1, the deliberately inoculated PC was divided into three equal parts and either 1) pooled with 5 half-volume, ABO- and Rh-identical PCs; 2) similarly pooled and white cell reduced; or 3) kept as a control. Sterile connections were used during pooling; modified storage containers were used to ensure the correct surface-to-volume ratio of the single unit.
Between Day 2 and Day 5 of storage, in 26 of 36 paired samples, nonfiltered pools containing Escherichia coli had greater total numbers of bacteria than did the paired single PCs. Day 2 pools had total bacteria levels approximately five times higher (colony-forming units/mL x container volume) than those in single units (p < 0.05). There was rapid growth of Staphylococcus aureus by Day 2 in pooled and unpooled PCs; by Day 3, total bacteria levels were approximately five times higher in pools than in single units (p < 0.05). Between Days 3 and 5 of storage, in 23 of 27 paired samples, nonfiltered pools containing S. aureus had greater total bacteria levels than the single PCs. By Day 5, 15 of 16 non-white-cell reduced pools had total levels of Staphylococcus epidermidis bacteria approximately five times those in the paired single PCs. Greater total bacteria levels in pooled units than in single units generally occurred when bacteria in pools reached the stationary phase of growth (when bacteria concentration became constant), and they were well correlated with the sixfold volume of pooled units. White cell reduction did not substantially affect the time required to attain stationary phase.
The potential during storage for greater total bacteria levels in pools than in single PCs is a consequence of the greater volume of the pool.
能够长时间储存血小板浓缩液（PCs）库将提供后勤灵活性。然而，因输注受污染的PCs而导致严重不良反应的报告促使人们研究，在储存含有故意接种的血小板单位的混合液后，其总细菌水平是否会与配对的未混合浓缩液中的水平有显著差异。
在第0天，将单个PC故意接种三种细菌中的一种（0.1 - 8.0菌落形成单位/毫升）。在第1天，将故意接种的PC等分为三份，然后分别进行以下操作：1）与5个半量、ABO和Rh血型相同的PCs混合；2）同样进行混合并去除白细胞；3）作为对照保存。混合过程中使用无菌连接；使用改良的储存容器以确保单个单位的正确表面积与体积比。
在储存的第2天至第5天期间，在36对样本中的26对中，含有大肠杆菌的未过滤混合液中的细菌总数比配对的单个PCs中的细菌总数更多。第2天混合液的总细菌水平（菌落形成单位/毫升×容器体积）比单个单位中的总细菌水平高约五倍（p < 0.05）。到第2天金黄色葡萄球菌在混合和未混合的PCs中均快速生长；到第3天，混合液中的总细菌水平比单个单位中的总细菌水平高约五倍（p < 0.05）。在储存的第3天至第5天期间，在27对样本中的23对中，含有金黄色葡萄球菌的未过滤混合液中的总细菌水平比单个PCs中的总细菌水平更高。到第5天，16个未去除白细胞的混合液中有15个的表皮葡萄球菌总水平约为配对单个PCs中的五倍。混合单位中的总细菌水平高于单个单位，这种情况通常发生在混合液中的细菌达到生长稳定期（细菌浓度变得恒定）时，并与混合单位六倍的体积密切相关。去除白细胞并未实质性影响达到稳定期所需的时间。
储存期间混合液中总细菌水平高于单个PCs的可能性是混合液体积更大的结果。
