New Preservative Increases Shelf Life Of Blood Platelets, Decreases Risk Of Harmful Reactions

In the wake of mass casualties from either natural disasters, such as the earthquake in Indonesia, or combat situations in Iraq and Afghanistan—extending the shelf life of platelets could have global implications for those in critical need of the blood product.

Platelets are the component of whole blood that control bleeding and prevent life-threatening hemorrhages. Patients undergoing a bone marrow transplant, cardiac surgery, chemotherapy, radiation treatment or organ transplants often require platelet transfusions.

"We found that by storing the platelets in the artificial preservative, we were able to retain the quality of the blood product for seven days, as opposed to having to dispose of them after only five days," says lead author Joseph Sweeney, MD, director of transfusion services at The Miriam Hospital and professor at Brown Medical School.

In addition, Sweeney and his team were able to reduce up to 80 percent 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.

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

The authors write that inadequate inventories of platelets due to their short shelf life and highly unpredictable demand, greatly limits blood centers' ability to provide platelets for essential transfusions. With a storage potential of seven 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more readily available to patients and provide a cost-savings to blood banks which discard millions of dollars worth of outdated platelets each year.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 two 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 seven, 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 seven days, it's important to note that the platelets in the preservative had extremely low plasma levels.

The artificial preservative tested was unique because it contained glucose, which seems to be a key component in extending the shelf life of platelets. The preservative also contained 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," says Sweeney.

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.

"Improvements in the quality and safety of blood products are continually being developed to enhance patient safety," Sweeney says. "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.