ANCHOR LEAD: WHY ARE BLOOD TRANSFUSIONS SOMETIMES HARMFUL? ELIZABETH TRACEY REPORTS
Blood transfusions are given only under dire circumstances, but sometimes they do more harm than good. One recent study suggests the reason may be lack of nitric oxide, a component of blood that often breaks down rapidly when blood is stored. Rick Lange, a cardiologist at Johns Hopkins, explains.
LANGE: This study suggests that one of the possible mechanisms for which transfusions may be harmful, and that is the person who receives the transfusion raises their blood count too high, may be the lack of nitric oxide in the transfused blood. Nitric oxide enlarges the vessel to accommodate the red blood cells to flow through them to deliver oxygen to the body. When one gives transfused blood that is deficient in nitric oxide, the blood vessels don’t expand, the red blood cells can get clogged in the vessels, and not deliver oxygen. This may be the mechanism whereby giving a person too many red blood cells may be deleterious. :31
Lange says more study is needed to see if nitric oxide can be preserved in stored blood. I’m Elizabeth Tracey reporting.