Sanz C, Pereira A, Vila J, Faundez A I, Gomez J, Ordinas A
Service of Hemotherapy, Hospital' clínico, Barcelona, Spain.
Transfusion. 1997 Mar;37(3):251-4. doi: 10.1046/j.1537-2995.1997.37397240204.x.
Previous studies have shown that cooling whole blood to 22 degrees C immediately after collection allows it to be held for up to 16 hours before component preparation (overnight-hold method) without a significant decrease in the quality of components obtained. A study was designated to evaluate the effect of the overnight-hold method on the growth of bacteria in experimentally contaminated blood units.
Twenty whole-blood units were inoculated with Staphylococcus epidermidis (300 colony-forming units [CFU]/mL; n = 10) or Escherichia coli (50 CFU/mL; n = 10) immediately after collection. Half the units of each group were fractionated 6 hours after collection and the other half after storage for 16 hours at 22 degrees C. Twenty additional whole-blood units were divided in two equal parts, one of which was white cell reduced before inoculation. These 40 half-units were inoculated with S. epidermidis or E. coli and processed by the overnight-hold method. The growth of bacteria was assessed in platelet concentrates on the second and fifth days of storage, in packed red cells on Day 35, and in fresh-frozen plasma after 60 days.
No bacteria growth was detected in plasma or red cell units. On the second day of storage, both bacteria strains grew more slowly in platelet concentrates obtained from blood processed by the overnight-hold method. This difference disappeared for S. epidermidis on the fifth day. When white cell-reduced and non-white cell-reduced whole-blood units were compared, platelet concentrates from the latter showed a delayed growth of both bacterial strains on the second and fifty days of storage.
Prolonged storage of whole-blood units at 22 degrees C before component preparation delays bacteria growth. This effect seems to be mediated by white cells.
先前的研究表明，采集后立即将全血冷却至22摄氏度，可使其在成分制备前保存长达16小时（过夜保存法），而所获得成分的质量不会显著下降。一项研究旨在评估过夜保存法对实验性污染血液单位中细菌生长的影响。
二十个全血单位在采集后立即接种表皮葡萄球菌（300菌落形成单位[CFU]/毫升；n = 10）或大肠杆菌（50 CFU/毫升；n = 10）。每组的一半单位在采集后6小时进行成分分离，另一半在22摄氏度下保存16小时后进行成分分离。另外二十个全血单位分成两等份，其中一份在接种前进行白细胞去除。这40个半单位接种表皮葡萄球菌或大肠杆菌，并采用过夜保存法进行处理。在储存的第二天和第五天评估血小板浓缩物中的细菌生长情况，在第35天评估红细胞中的细菌生长情况，在60天后评估新鲜冰冻血浆中的细菌生长情况。
在血浆或红细胞单位中未检测到细菌生长。在储存的第二天，两种菌株在通过过夜保存法处理的血液中获得的血小板浓缩物中生长较慢。对于表皮葡萄球菌，这种差异在第五天消失。当比较白细胞去除和未去除白细胞的全血单位时，后者的血小板浓缩物在储存的第二天和第五天显示两种菌株的生长延迟。
在成分制备前将全血单位在22摄氏度下长时间保存会延迟细菌生长。这种效应似乎是由白细胞介导的。
