In 1997 the Stroke Prevention Trial in Sickle Cell Anemia, funded by the National Heart, Lung, and Blood Institute (NHLBI), found that periodic red blood cell transfusions reduce the rate of stroke in children with sickle cell anemia by 90%. However, the good news came with a caveat: long-term use of blood transfusion can have adverse effects, such as iron overload, alloimmunization, and infections.
Because of these risks, in 2000 the NHLBI launched a second study to determine whether periodic transfusions could be discontinued safely in children who, after at least 30 months of therapy, had never had a stroke and had responded well to transfusion therapy. Researchers divided 79 children, ages two to 18 years, who had sickle cell anemia and had received transfusions for at least 30 months, into two groups-one continuing to receive periodic blood transfusions, the other not. Although the researchers had hoped to increase the patient pool to 100, they halted recruitment and the trial last December, after two children in the second group had strokes and 14 others developed a high risk of stroke, as determined through transcranial Doppler ultrasonography.
The NHLBI recommends that until researchers find ways to identify which children can safely stop receiving them, periodic blood transfusions be continued, despite potentially adverse effects.-Dalia Sofer