Detection of bacterial contamination in apheresis platelets: is apheresis technology a factor?

BACKGROUND: Apheresis platelet (AP) contamination may be influenced by manufacturing methods because bacteria are subject to the same forces that permit separation of blood cells. This study assesses whether apheresis technology influences in-process detection of bacterial contamination. STUDY DESIGN AND METHODS: Blood Systems, Inc. (BSI) and New York Blood Center (NYBC) use Amicus and Trima devices to collect APs. Manufacturing (arm disinfection and in-line diversion) was consistent for both devices in the study period. Detection was performed using BacT/ALERT. True-positive (TP) rates were calculated and significance testing was performed using chi-square tests separately for BSI and NYBC. For BSI, multivariable logistic regression analysis was also performed to identify factors associated with TP results. RESULTS: For BSI, there were 49 TPs in 354,946 donations (1.4/10,000): 2.5 per 10,000 for Amicus and 1.0 per 10,000 for Trima (p < 0.05). Multivariable logistic regression analysis showed significant association between TP and devices (odds ratio, 2.8; 95% confidence interval [CI], 1.01-8.0) and for one collection region. For NYBC, there were 18 TPs in 161,840 donations (1.1/10,000): 2.1 per 10,000 for Amicus and 0.4 per 10,000 for Trima (p < 0.05). CONCLUSIONS: The TP rate was significantly higher in Amicus collections than in Trima collections at NYBC and BSI. These results do not allow for conclusions regarding the relative clinical risk of PLTs collected by Amicus and Trima. Future evaluations of component quality and clinical outcomes should consider different collection technologies.