The maximum storage limit of red blood cells is six weeks, however, researchers from New York City-based Columbia University Medical Center have found that six-week-old blood could harm transfusion patients.
The researchers examined a group of 60 volunteers who received a unit of red blood cells that had been stored for one, two, three, four, five or six weeks. The participants were then monitored for 20 hours after transfusion.
The researchers published their findings in the Journal of Clinical Investigation.
Seven of the nine volunteers who received the six-week-old blood could not appropriately metabolize the damaged cells, leading to the release of iron in large amounts into their bloodstream. This occurred within hours after transfusion. Only one volunteer who received blood stored for five weeks or less had a similar response.
While none of the volunteers were harmed, previous studies have shown that excess iron can enhance blood clots and promote infections. Thus, the researchers recommend that the FDA reduce the maximum storage limit for blood.
"Our recommendation will be controversial, but we think we have real data to support it," said Steven Spitalnik, MD, professor of pathology & cell biology at CUMC and medical director of the clinical laboratories at NewYork-Presbyterian/Columbia and the study's co-leader. "Recent studies have concluded that transfusing old blood has no impact on patient outcomes, but those studies didn't exclusively examine the oldest blood available for transfusions. Our new study found a real problem when transfusing blood that's older than five weeks."