Old blood boosts risk of infection

Hospitalized patients who received blood that had been stored for more than four weeks were nearly three times as likely to develop infections as those who received fresher blood, researchers said. The blood itself was not infected, but the release of chemical agents called cytokines by the stored blood may have affected the recipient's immune systems, rendering them more susceptible to infections, said Raquel Nahra, MD, of the Sparks Regional Medical Center in Ft. Smith, AK. The patients typically suffered an increase in urinary tract infections, pneumonia, and infections associated with intravenous lines, she told a Philadelphia meeting of the American College of Chest Physicians.