The oldest blood accessible for transfusions releases large and possibly harmful amounts of iron into patients' bloodstreams, a new study by scholars at Columbia University Medical Center (CUMC) has found.
Based on the new discoveries, the researchers endorse that the FDA reduce the maximum storage limit of red blood cells from 6 weeks to 5 weeks, if there are adequate blood stores available.
"Our position will be provocative, but we think we have real data to support it," said the study's co-leader Steven Spitalnik, MD, professor of pathology & cell biology at CUMC and medical director of the clinical research laboratory at NewYork-Presbyterian/Columbia. "Recent studies have resolved that transfusing old blood has no impact on patient consequences, but those studies didn't wholly examine the oldest blood available for transfusions. Our new study initiate a real problem when infusing blood that's older than 5 weeks."
Finding Shows Significant And Vital Information On Why Old Blood Should Not Be Use Anymore
Transfusion of red blood cells is the most common procedure completed in hospitalized patients, with around 5 million patients receiving red blood cell transfusions yearly in the United States. "But the longer you stock blood, the more the cells become spoiled," said the study's co-leader Eldad Hod, MD, associate professor of pathology & cell biology at CUMC and clinical pathologist at NewYork-Presbyterian/Columbia. Currently, the U.S. FDA allows units of red blood cells to be stored for up to 6 weeks before they must be discarded.
In the study, the scientists randomly allocated a group of 60 healthy volunteers to receive a unit of red blood cells that had been stored for 1, 2, 3, 4, 5, or 6 weeks. The volunteers were then observed for 20 hours after transfusion.
Within hours afterwards transfusion, 7 of the 9 volunteers who received the 6-week-old blood could not suitably metabolize the damaged cells, in that way releasing large amounts of iron into their bloodstream. Only one volunteer who transfuse younger blood had a similar response, with blood had been kept for five weeks.
None of the volunteers were injured by the transfusion, but earlier studies have shown that excess iron can improve blood clots and promote infections. "Based on the amount of iron circling around the blood of those who have received 6-week-old blood, we'd predict that certain existing contaminations could be exacerbated," said Dr. Hod.
"Therefore, for ill, hospitalized patients, this excess iron could lead to serious problems," said Dr. Spitalnik says.
The true impact of 6-week-old blood on the rate of problems in patients is likely to be small, the scientists say, but since millions of Americans receive transfusions each year, even a 1 percent variance in complications could affect many patients.
"Based on our verdicts of potential harm, we think the sensible thing to do now is for the FDA to reduce the maximum storing period," said Dr. Spitalnik. "The U.K., Ireland, the Netherlands, and the National Institutes of Health have limited storing to 35 days, and we think that can be achieved all over the U.S. without seriously stirring the blood supply."