Transfusions cut stroke risk in sickle-cell patients

By Gene Emery

BOSTON (Reuters) – Some patients with severe sickle cell
disease may need a lifetime of blood transfusions to reduce the
chances of suffering a stroke, data from a new study show.

Scientists had hoped that patients with blood disease could
be treated with a limited number of transfusions. But the
study, published in this week’s New England Journal of
Medicine, found that the stroke risk reappeared after blood
exchanges were stopped.

“We hoped that maybe we were dealing with something that
was relatively short-lived over a few years in a child’s life,”
said Robert Adams, chief author of the study, referring to the
need for a continued fresh supply of donated red blood cells.

The study’s result, he said, was “a disappointment.”

Sickle-cell disease is a genetic disorder that causes
normally flexible red blood cells to contort into a
crescent-moon shape that makes them clump, blocking blood
vessels and causing most patients bouts of intense pain.

About 1 in 650 African-Americans and up to 1 in 1,000
Latinos in the United States have some form of sickle cell
disease.

Roughly 10 percent of those patients, who have narrowed
blood vessels in the brain, face a higher-than-average chance
of stroke. Those patients with the higher risk have a 1 in 10
chance of actually having a stroke in a given year.

Regular transfusions of red blood cells typically cut the
stroke risk by 90 percent.

Because the blood-flow pattern in the brain seems return to
normal in many patients who receive transfusions, doctors had
hoped that the need for extra blood was only temporary.

To test that assumption, the team led by Adams, a stroke
specialist at the Medical College of Georgia, decided to halt
the transfusions in 50 children, but continue them in another
50.

Preliminary results, after only 79 patients were included
in the study, showed that discontinuing the transfusions would
be dangerous.

Two children who did not receive fresh blood cells
regularly suffered a stroke and 14 others showed a dangerous
increase of blood flow in the brain.

There were some exceptions, Adams said.

“There are a few kids who tolerate being taken off
transfusion. It’s just that we can’t really figure out in
advance who they are,” the researcher told Reuters.

Even when doctors perform regular ultrasound testing to
track changes in blood flow through the brain, “you do have the
chance of a breakthrough stroke, as has happened in two of the
cases,” Adams said.