Blood Simple

Blood mix-ups, though rare, arestill one of the most feared mistakes in transfusion medicine. "It'sthe biggest threat today," says Dr. Kathleen Sazama, a transfusionexpert at the University of Texas M.D. Anderson Cancer Center inHouston. Even an ounce of mismatched cells can trigger a potentiallylethal immune response, causing blood clots and internal bleeding. Butnow scientists at a Massachusetts biotech firm may be on the brink ofeliminating most transfusion errors and ensuring a steady supply ofblood to the nation's hospitals. Their solution is a device thatconverts all blood into type O, the most coveted of the four majorblood types because it can be safely transfused into nearly anypatient. "Press 'start,' and the machine does everything else," saysDouglas Clibourn, the CEO of ZymeQuest.

The secret to the device, roughlythe size of a dishwasher, is a pair of enzymes newly discovered byHenrik Clausen of the University of Copenhagen in Denmark that cancleave sugar molecules from the surface of the red blood cells. Thesemolecules, called antigens, stud the cell membrane and determine whethersomeone is type A, B, AB or O. If you receive the wrong blood, antigensin your blood plasma elicit antibodies to attack the foreign antigens.

The ability to turn much of thenation's blood supply into type O could be a boon for hospitals, whichuse it in trauma cases when there's little time to determine thepatient's true blood type. Routine shortages also can put them in apinch. ZymeQuest's machine churns out eight units of type O every 90minutes.

Source: popsci.comAdded: 16 August 2007