Transfusions of 'Old Blood' Could Have An Adverse Effect On Patients [STUDY]

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A recent study by researchers at Columbia University Medical Center (CUMC) found that the transfusion of blood stored for six weeks releases large and potentially harmful amounts of iron into a patient's bloodstream.

The researchers recommend Based on their findings, that the FDA reduce the maximum storage limit of red blood cells from six weeks to five weeks, as long as there are sufficient blood supplies available.

Although, preliminary studies have concluded that the transfusion of old blood has no impact on patient outcomes, they did not exclusively examine the oldest blood available for transfusions. This new study discovers a real problem when transfusing blood that is older than five weeks.

The longer blood is kept in storage, the more its cells become damaged, according to the study's co-author and an associate professor of pathology and cell biology at CUMC and also clinical pathologist at NewYork, Presbyterian/Columbia, Eldad Hod, MD.

Eurekalert reported that the United States FDA allows units of red blood cells to be stored for up to six weeks after which they must be discarded. The researchers randomly assigned 60 healthy volunteers to different groups to receive a unit of red blood cells that had been stored for one to six weeks and were monitored for 20 hours after transfusion.

Few hours after transfusion, seven out of the nine volunteers who received blood stored for six weeks could not metabolize the damaged cells appropriately, thereby releasing large amounts of iron into their bloodstream. Only one volunteer who received blood stored for five weeks had a similar response.

However, none of the volunteers were harmed by the transfusion, but previous studies have shown that excess iron can enhance blood clots and increase the risk of infections. Based on the amount of iron circulating in the blood of the volunteers who received the old blood, we could predict that certain existing infections could be exacerbated, Dr. Hod said.

But for sick, hospitalized patients, the excess iron could lead to serious complications, according to the study's co-author Steven Spitalnik, MD, professor of pathology and cell biology at CUMC and also medical director of the clinical laboratories at NewYork, Presbyterian/Columbia.

Although, the researchers noted the true impact of the 6 weeks old blood on the rate of complications in patients may not be much, but since millions of Americans receive transfusions every year, even a 1 percent difference in complications could affect a large number of patients, according to Science Daily.

The researchers estimate that around 10-20 percent of blood units used for transfusions have been stored for more than 5 weeks, which makes the number of patients who are likely to receive a unit of very old blood substantial.

Therefore, they recommend based on this findings of potential harm, that the prudent thing to do at this time is for the FDA to reduce the maximum storage period.

The United Kingdom, Ireland, the Netherlands and the National Institutes of Health have limited blood storage to 35 days and the authors think that it can also be achieved in the United States without affecting the blood supply.

The researchers acknowledged that there are no conflicts of interests. The study is titled, "Prolonged red cell storage before transfusion increases extravascular hemolysis." The study was funded by grants from the National Institutes of Health (HL115557 and UL1TR000040).

They published their findings in the January issue of the Journal of Clinical Investigation.