Study Shows New Preservative Increases Shelf Life of Blood Platelets

A new study has found that storing whole blood derived platelets in an artificial preservative can extend their shelf life and produce a safer end product. This is the finding of a research paper appearing in the May 2006 issue of Transfusion by researchers at The Miriam Hospital in Providence, RI. The artificial preservative tested contained glucose, sodium acetate and sodium bicarbonate.

"Until now, preservatives containing glucose have not been successfully used for platelet storage because glucose carmelizes during sterilization, and the only way to prevent carmelization is to lower the pH levels to a point that could be harmful to the platelet," said lead author Joseph Sweeney, MD, director of transfusion services at The Miriam Hospital and professor at Brown Medical School.

Sweeney was able to use a glucose-containing preservative without harming the platelets by adding sodium bicarbonate to the storage container. The sodium bicarbonate protected the platelets from exposure to low pH levels. "We found that by storing the platelets in the artificial preservative, we were able to retain the quality of the blood product for 7 days, as opposed to having to dispose of them after only 5 days," he said.

In addition, Sweeney and his team were able to reduce up to 80% of the plasma in the platelets stored in preservative. Since plasma is responsible for the majority of the adverse reactions that transfusion patients may experience, this suggests that those receiving transfusions will better tolerate the new blood product.

"Currently, platelets are stored in plasma and discarded after five days," he said. "Significantly reducing the amount of plasma would likely lessen the frequency of these adverse events."

The authors wrote that inadequate inventories of platelets due to their short shelf life and highly unpredictable demand greatly limit blood centers' ability to provide platelets for essential transfusions. With a storage potential of 7 days or longer, platelets can be more readily available to patients and provide a cost-savings to blood banks which discard millions of dollars worth of outdated platelets each year.

Researchers monitored 2 groups of platelets derived from whole blood donations. The first group of platelets was stored in plasma, while the second group was stored in the artificial preservative. On day 7, both groups of platelets met the current FDA requirements and the more stringent European requirements for use. Although both groups of platelets retained their quality for 7 days, it's important to note that the platelets in the preservative had extremely low plasma levels.

"Improvements in the quality and safety of blood products are continually being developed to enhance patient safety," Sweeney said. "Advances in platelet storage will pave the way for the next generation of blood products, such as artificial platelets."

The research was supported by a grant from Pall Corporation.