The oldest blood available for transfusions releases large and potentially harmful amounts of iron into patients’ bloodstreams, warns a new study which recommends reducing the maximum storage limit of red blood cells from six to five weeks.
Researchers at Columbia University Medical Centre (CUMC) in the US randomly assigned a group of 60 healthy volunteers to receive a unit of red blood cells that had been stored for one, two, three, four, five or six weeks.
The volunteers were then monitored for 20 hours after transfusion. Within hours after transfusion, seven of the nine volunteers who received the six-week-old blood could not appropriately metabolise the damaged cells, thereby releasing large amounts of iron into their bloodstream.