Teenage Boy Develops Tumors After Stem Cell Treatment
Israeli scientists said on Tuesday that a boy treated with fetal stem cells for a rare brain disease had developed benign tumors in his brain and spinal chord.
The 17 year-old boy received the stem cells in 2001 at a Moscow hospital and is now showing brain and spinal tumors four years later, PLoS Medicine reports.
It is the first documented case of a human brain tumor after fetal stem cell therapy and scientists say it is a crucial development that highlights the need for further study in stem cell research.
Dr. John Gearhart, a stem cell scientist at the University of Pennsylvania, is warning desperate U.S. patients who head abroad to clinics that offer unproven stem cell injections to be wary of the unknown consequences.
"Cells are not drugs. They can misbehave in so many different ways, it just is going to take a good deal of time to prove how best to pursue the potential therapy," Gearhart said.
Some scientists fear the possibility that stem cells may turn cancerous. Other believe it is possible that stem cell therapy could unwittingly pass viruses and other disease causing agents to people who receive cell transplants.
The Israeli boy was treated for an extremely rare condition called Ataxia Telangiectasia – a genetic disease that attacks the brain region controlling movement and speech.
Doctors gave him three courses of fetal stem cell injections to the brain and the fluid surrounding the spine.
Four years after the treatment, doctors at the Sheba Medical Center in Tel Aviv discovered two tumors “” one in the spine and one in the brain at the same sites the injections had been given.
The non-cancerous tumor was removed from his spine a year later and was found to contain cells that could not have arisen from the patient’s own tissue and had most likely grown from the donated stem cells.
Researchers believe the donor-derived cells might have sparked the tumors because people with Ataxia Telangiectasia often have a weakened immune system. It is unclear whether the stem cell therapy helped his genetic condition.
Although the findings do not imply that the research in stem cell therapeutics should be abandoned, many researchers agree more work should be done to assess the safety of this therapy.
Stem cell scientist Dr. Stephen Minger, of King’s College London, told BBC News it was clear that the tumors had arisen from the transplanted cells.
"This is worrying and we have to be cautious. We need to have long term monitoring and follow up of the patients given stem cells and rigorous regulation of centers providing cell therapy.
"Although this is just one case it does show that we need to be careful about the cell populations we are using."
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Image Caption: A colony of embryonic stem cells, from the H9 cell line (NIH code: WA09). Viewed at 10X with Carl Zeiss Axiovert scope. Courtesy Wikipedia
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