Calgary doctors develop new stem-cell transplant procedure to cure children with sickle cell anemia
When she was just six months
old, Cardelia Fox had a stroke — the first of three she would experience as a child.
At the time, doctors told her parents she wouldn’t live past five because she suffered from sickle cell anemia, a genetic blood disorder in which
abnormal sickle-shaped red blood cells hinder the flow of oxygen through the body.
Now 19, the bubbly Calgarian of Jamaican descent is cured of the disease thanks to a new stem-cell transplant procedure being spearheaded among children
by the Alberta Children’s Hospital with potentially global implications.
“It’s really a breakthrough,” said Anna Banerji, a pediatrician and professor at the University of Toronto. “This could make a huge difference
in the life of a child.”
To date, the hospital has successfully cured sickle cell anemia in nine children with a new protocol for stem-cell transplants, which involves a bone marrow
donation from a sibling who is a 100 per cent match, but does not have sickle cell anemia. The odds a patient has such a sibling are one in five.
Stem-cell transplants for children and teenagers with sickle cell anemia have grown increasingly common
in recent years and are carried out in many hospitals in the U.S. and Europe, said George Buchanan, professor of pediatrics at the University of Texas Southwestern Medical Centre.
But Alberta Children’s approach is unique because it is likely
the first place to conduct transplants on children that don’t involve chemotherapy, said Gregory Guilcher, a pediatric oncologist who leads the sickle cell blood and marrow transplant program at Alberta Children’s Hospital, during
an interview at a media briefing on Monday.
Drawing on a treatment used successfully on adults in the U.S., sick children at the hospital are instead given medications that intensively suppress their immune system and a low dose of radiation
in the week before the transplant.
This “lighter” treatment is less risky than chemotherapy, which can come at the cost of infertility and is more likely to cause graft-versus-host disease in which the transplanted bone marrow creates
serious complications by rejecting the patient’s body, Guilcher explained.
“We basically knock out the immune system and we deplete the bone marrow blood cells with the radiation, and this allows space and an environment that
can allow a person to accept the new blood system without destroying it right away,” said Guilcher, who has received calls from people around the world who are interested in the approach.
For her part, Fox said that the transplant she received
from her elder sister when she was 17 transformed her into a “whole new person.”
“The greatest thing is to not have those people that would make her ill.
Prior to being cured, Fox miserably looked ahead to a life
filled with monthly blood transfusions that involved spending a whole day at the hospital. Though a necessary treatment, the transfusions left her exhausted, pulled her away from school and made her upset, said Fox.
She had the words
“set free” tattooed on her forearm on her 19th birthday to symbolize a new chapter in her life.
Only a handful of the millions who suffer from sickle cell anemia and other hemoglobin disorders can be as lucky as Fox.
The majority with sickle cell anemia, which is caused by a gene that is protective against malaria, are in poor countries in Africa, though it also affects those of Middle Eastern, Indian and Mediterranean descent.
“For 95% of the
world where people with sickle cell anemia live, this not an option at all right now,” said Buchanan, noting that stem cell transplants often cost US$100,000 to $150,000.
Guilcher has ambitions to change that in partnership with doctors
in Nairobi, who have extensive experience that can also help doctors in Canada.
“The number of kids they see with sickle cell disease is huge. There are thousands even in Nairobi slums,” said Guilcher, noting that many go untreated.
His team hopes to increase access to the cure by working on a teaching curriculum to train more East African doctors in transplant techniques and by establishing an East African bone marrow transplant centre in five to ten years.
hope that some day everyone with sickle cell disease will have the option of a cure,” he said
be there anymore to tell me things I cannot do,” said Fox, whose rebellious streak prompted her to do forbidden things, such as drinking a Jamaican
grapefruit drink and intense exercise