Searching for safer red blood cell bags for pediatric recipients

The most widely used plasticizer in blood bags is called DEHP. DEHP is also found in toys, medical tubing, water bottles, rainwear and many other goods. Despite DEHP’s extensive use, there are concerns about its toxicity. There is no clear evidence that DEHP has harmful effects in humans following transfusion or exposure to other medical devices, but animal studies have shown that it may affect the development of the reproductive system, particularly in males. Due to the possibility of harm, a Health Canada Expert Advisory Panel recently concluded that alternatives to DEHP-containing medical devices should be sought, especially when foetuses, newborns, infants and young children are concerned. Several alternative plasticizers are available but it is not clear how well blood products will store in bags made with these other plasticizers.

This is a concern for red blood cells, as an unexpected effect of using DEHP blood bags was the finding that red blood cells store very well and have better quality in these bags than in others. To explore alternative plasticizers, these studies compared the quality of red blood cells stored in bags specifically designed for pediatric patients plasticized either with DEHP or two less toxic plasticizers called DINCH and BTHC.

• Metabolism of the red blood cells was affected by the bag they were stored in. Metabolism was best maintained in DINCH bags, and worst in BTHC bags.
• Red blood cells in BTHC bags had more signs of damage: they had the greatest release of potassium and the highest levels of hemolysis (rupture or bursting of red blood cells). By the end of the storage period, hemolysis levels in BTHC bags were higher than the 0.8 per cent limit set by Canadian Standards Association guidelines.
• Arrangement of phospholipids, an important structural part of red blood cell membranes, was not different among the bags.
• Red blood cells stored in BTHC bags were larger, more rigid and more sensitive to hemolysis than red blood cells stored in the other containers. This indicates that the red blood cell membrane was less damaged and better preserved in DEHP and DINCH bags than in BTHC bags.
• Overall, red blood cells in DEHP and DINCH bags showed good quality, while red blood cells in BTHC bags stored poorly.

This research was conducted in the laboratories of Dr. Dana Devine, Canadian Blood Services chief medical and scientific officer and a professor in the department of pathology and laboratory medicine at the University of British Columbia, Vancouver, B.C. and Dr. Jason Acker, a Centre for Innovation senior development scientist and a professor in the department of laboratory medicine and pathology at the University of Alberta, Edmonton, Alta. In Dr. Devine’s laboratory, the research was led by Dr. Katherine Serrano, a research associate with the Centre for Innovation and a clinical assistant professor at the department of pathology and laboratory medicine at the University of British Columbia. In Dr. Acker’s laboratory, the research was led by Dr. Beatriz Bicalho, a postdoctoral fellow at the Centre for Innovation, Edmonton, Alta. The work was conducted in collaboration with Fresenius-Kabi Deutschland GmbH, Bad Homberg, Germany.