Blood Transfusions May Cut Stroke Risk From Sickle Cell
Study found children who got monthly infusions were less likely to suffer another attack
By Amy Norton
WEDNESDAY, Aug. 20, 2014 (HealthDay News) -- Monthly blood transfusions may lower the chances of "silent" strokes in some children with sickle cell anemia, a new clinical trial indicates.
The study, reported in the Aug. 21 issue of the New England Journal of Medicine, found that in children with a previous silent stroke, monthly blood transfusions cut the rate of future strokes by more than half.
The researchers said their findings support screening children with sickle cell for evidence of silent stroke -- something that is not routinely done now.
"Prior to this, there was no treatment, so the argument was, 'Why screen?'" explained Dr. James Casella, vice chair of the clinical trial and director of pediatric hematology at Johns Hopkins Children's Center in Baltimore. "Now we have a treatment to offer."
However, Casella also stressed that "this study is a first step, not the last one."
Many questions remain, he said. A big one is, do the blood transfusions have to be continued for life?
"It's possible the treatment could be indefinite," Casella said.
Sickle cell anemia is an inherited disease that mainly affects people of African, South or Central American or Mediterranean descent. In the United States, about one in 500 black children are born with the condition, according to the U.S. National Institutes of Health.
The central problem in sickle cell is that the body produces red blood cells that are crescent-shaped, rather than disc-shaped. Those abnormal cells tend to be sticky and can block blood flow.
About one-third of children develop problems with blood flow to the brain, including strokes and silent strokes -- so called because they cause no obvious symptoms, but leave behind areas of tissue damage in the brain.
For the new study, Casella's team used MRI brain scans to screen over 1,000 sickle cell patients between the ages of 5 and 15 for signs of a past silent stroke. In the end, 196 children with a previous stroke were randomly assigned to one of two groups: one received monthly blood transfusions, and one stayed with usual care.
Over three years, 6 percent of kids in the transfusion group had a new silent stroke or, in one case, a full-blown stroke. That compared with 14 percent of kids in the other group.
While the study found an association between blood transfusions and a lower risk of a silent stroke, it did not prove a direct cause-and-effect link.
What is the benefit of preventing silent strokes?
Casella said the brain injury can lower a child's IQ and impair "executive function" -- vital mental abilities such as focusing attention, planning and organizing.
In this study, there was no evidence that kids on transfusions had higher IQs or sharper mental function.