Prolonging platelets’ shelf life

A little dab of sugar may double the shelf life of blood platelets, a lifesaving clotting component that is in chronic short supply because of spoilage.

Harvard University researchers reported last week in the journal Science that laboratory tests show that putting a small amount of galactose, a type of sugar, into isolated platelets allows the blood components to be refrigerated and usefully preserved for at least 12 days.

That more than doubles the shelf life of the current practice, which is to store the platelets at room temperature for only five days. Because of spoilage, more than 25% of all platelets taken from donated blood must be discarded.

If platelets are refrigerated, as whole blood is, they undergo a chemical change that makes them the target of macrophages, one of the body’s immune cells. When chilled platelets are transfused, they are engulfed and killed by the macrophages. For this reason, platelets are stored at room temperature and become useless after five days.

A team of researchers at Harvard and Brigham and Women’s Hospital in Boston has found that platelets can be refrigerated and remain useful for about 12 days if they add a small amount of galactose.

Dr. Karin M. Hoffmeister, first author of the Science study, said macrophages attack chilled platelets because the immune cell targets another type of sugar on the surface of the transfused cell.

Adding galactose covers up that other sugar and protects the platelets from the macrophages.