Sickle Cell Children Should Continue Transfusions

A clinical trial has been halted early because of the finding that stopping blood transfusions in children with sickle cell anemia results in a high risk of stroke. The trial was conducted by the U.S. National Heart, Lung, and Blood Institute (NHLBI; Bethesda, MD, USA).

The trial, called Stroke Prevention Trial II (STOP II), was studying whether some children with sickle cell anemia at high risk for stroke could at some point after a minimum of 30 months (range 30-91months) safely stop receiving periodic blood transfusions designed to prevent strokes. The results showed a return to high risk of stroke in children who stopped receiving the transfusions. The findings were presented at the annual meeting of the American Society of Hematology in San Diego (CA, USA) in December 2004.

At the time the study was halted, 14 of the 41 patients randomly assigned to stop transfusions reverted to high risk of stroke as measured by transcranial Doppler (TCD) ultrasound screening. A high blood-flow velocity in one or more major arteries of the brain is linked with narrowing in key blood vessels supplying the brain, which increases the risk of stroke. Patients in the transfusion arm of the study received blood transfusions every three to four weeks to keep the amount of sickle hemoglobin in their blood to no more than 30% of total hemoglobin. One long-term effect of transfusion is iron overload, which can be treated with chelation therapy.

"Now we know that for high-risk patients, it is not safe to stop transfusions even if the TCD shows a return to normal range,” observed principal investigator Robert Adams, M.D., professor of Pediatrics, Medical College of Georgia (Augusta, USA), who presented the findings. "We need to weigh carefully the risks of this preventive therapy and make sure we monitor patients closely with TCD. We also need to come up with a better way to maintain the stroke prevention benefit while lowering the side effects of transfusion treatment.”




Related Links:
U.S. National Heart, Lung, and Blood Institute