The Precious Gift of Platelets

Article excerpt


While "well preserved" may be insulting in some circumstances, doctors depend on steady supplies of well-preserved blood to treat patients. A new discovery in that area may one day help patients stay better preserved.

In research published Friday in the journal Science, a team of researchers, led by Karin Hoffmeister of Brigham and Women's Hospital and Harvard Medical School, discovered a way to more than double the storage life of blood platelets by masking a specific sugar molecule on clusters of them.

Platelets cluster when they are cooled down to near-freezing temperatures thanks to certain receptors on their surface. They stay clumped together once warmed, which macrophages - specialized white blood cells which sweep up and destroy foreign objects - home in on. However, by masking the platelet's receptor sugar with a different sugar molecule, one that is already found in cells, the researchers were able to increase their post-transfusion survival dramatically.

They worked primarily with mice, but their work also represents an important development for sugar-based therapies in humans. Sugars play a vast, complex role in cellular recognition and signaling. As Thomas Mader noted in a survey article in the July 2002 issue of Scientific American, "So ubiquitous are these molecules that cells appear to other cells and to the immune system as sugarcoated." However, the 10 simple sugars common in mammals stack in many different ways, and so it has been difficult for researchers to decipher their structures and functions, and even more troublesome for them to design therapeutic applications. …