Frequent blood transfusion therapy lowers recurrence of strokes in children with sickle cell anemia who already suffer pre-existing silent strokes, according to a Vanderbilt-led study.

Nearly 100,000 people in the United States are diagnosed with sickle cell disease, a group of inherited blood disorders. The disease that commonly affects African-Americans involves red blood cells that are abnormal - hard, sticky and shaped like a crescent moon.

When the sickle cells travel through small blood vessels, they decrease the normal blood flow to all organs of the body, causing lung disease and a shortened lifespan among others.

Silent strokes are a common phenomenon in sickle cell anemia (the most common form of sickle cell disease). It occurs in approximately 3 percent of school-aged children with the disease, causing poor performance in school and other complex tasks. These children are at a higher risk of suffering from dangerous overt strokes and new or enlarged silent stokes.

The only way to diagnose a silent stroke is with magnetic resonance imaging (MRI) of the brain.

For the study, the researchers involved 29 clinical centers in the United States, France, Canada and the United Kingdom. Overall 196 children, aged between 5 and 15 years, had no history of stroke but had one or more silent strokes confirmed by MRI.

The Silent Cerebral Infarct Transfusion (SIT) trial wanted to determine the effectiveness of blood transfusion therapy in children with sickle cell anemia to prevent repeat cerebral infarcts (overt strokes and silent strokes).

The researchers found that monthly blood transfusions lowered the reappearance of cerebral infarcts by 58 percent in children with pre-existing silent strokes as compared to the observation group.

"The study indicates that screening for silent strokes in children starting school can lead to early detection and prevention of recurrences as well as reduction in other complications of sickle cell anemia such as acute painful episodes and acute chest syndrome. The results of this trial will make a difference to children with sickle cell anemia and their families," said Deborah Hirtz, program director at the National Institute of Health's National Institute of Neurological Disorders and Stroke (NINDS), in a press release.

The finding is published in the New England Journal of Medicine.

Tags Blood, Children, Disease, Vanderbilt