Effect of leukoreduction and temperature on risk of bacterial growth in CPDA‐1 whole blood: A study of Escherichia coli

Abstract

Background Collection of non‐leukoreduced citrate‐phosphate‐dextrose‐adenine (CPDA‐1) whole blood is performed in walking blood banks. Blood collected under field conditions may have increased risk of bacterial contamination. This study was conducted to examine the effects of WBC reduction and storage temperature on growth of Escherichia coli (ATCC® 25922™) in CPDA‐1 whole blood. Methods CPDA‐1 whole blood of 450 ml from 10 group O donors was inoculated with E. coli. Two hours after inoculation, the test bags were leukoreduced with a platelet‐sparing filter. The control bags remained unfiltered. Each whole blood bag was then split into three smaller bags for further storage at 2–6°C, 20–24°C, or 33–37°C. Bacterial growth was quantified immediately, 2 and 3 h after inoculation, on days 1, 3, 7, and 14 for all storage temperatures, and on days 21 and 35 for storage at 2–6°C. Results Whole blood was inoculated with a median of 19.5 (range 12.0–32.0) colony‐forming units per ml (CFU/ml) E. coli. After leukoreduction, a median of 3.3 CFU/ml (range 0.0–33.3) E. coli remained. In the control arm, the WBCs phagocytized E. coli within 24 h at 20–24°C and 33–37°C in 9 of 10 bags. During storage at 2–6°C, a slow self‐sterilization occurred over time with and without leukoreduction. Conclusions Storage at 20–24°C and 33–37°C for up to 24 h before leukoreduction reduces the risk of E. coli‐contamination in CPDA‐1 whole blood. Subsequent storage at 2–6°C will further reduce the growth of E. coli.

In vitro quality and hemostatic function of cold‐stored CPDA‐1 whole blood after repeated transient exposure to 28°C storage temperature

“…The effect of storage on hematological parameters confirmed the results from other studies on CPDA‐1 whole blood, 17–20 with stable hemoglobin and hematocrit, and a decrease in platelet count and WBC count. Aggregates prevented accurate counting of platelets in two of the test bags, one on day 7 and one on day 35.…”

“…Additionally, a recent study showed that the presence of WBCs might be beneficial if the blood is stored is stored at higher temperatures. 17 In conclusion, repeated transient exposure of coldstored CPDA-1 whole blood to 28°C for a 4-h period followed by a return to 4°C once a week over a 35-day period did not have any notable negative impact on the measured quality parameters and hemostatic function. The effect on hemolysis beyond three cycles over 21 days was uncertain and warrants further investigation.…”

“…The use of a sample diversion pouch can further reduce the risk, 27–29 something the CPDA‐1 collection bags we used did not have. Additionally, a recent study showed that the presence of WBCs might be beneficial if the blood is stored is stored at higher temperatures 17 …”

Assessment of bacterial growth in leukoreduced cold‐stored whole blood supports overnight hold at room temperature prior to filtration: A pilot study

“…Bacteria that resist immune clearance prior to WB leukoreduction, may not necessarily proliferate during cold storage as recently shown by Braathen et al [15]. In their study, Escherichia coli , which was not fully eliminated before WB leukoreduction, did not replicate during storage at 2–6°C.…”

“…Bacteria that resist immune clearance prior to WB leukoreduction, may not necessarily proliferate during cold storage as recently shown by Braathen et al [15]. In their study, Escherichia coli, which was not fully eliminated before WB leukoreduction, did not replicate during storage at 2-6 C. However, the safety risk posed by bacteria able to proliferate in CWB (i.e., psychrotrophic) was described by James and Stocks in 1957 [16].…”