A simple blood stem cell transplant is showing strong promise for treating several metabolic, blood, and immune disorders, including thalassemia and some leukodystrophies.
A rare condition
These conditions are rare, affecting fewer than 200,000 people in the U.S., so funding for new therapies is often limited. Researchers at UPMC Children’s Hospital of Pittsburgh set out to develop a single therapy that could help multiple disorders without creating separate treatments for each one.
The team used blood stem cells from donated umbilical cords and placentas. In a news article, senior author Dr. Paul Szabolcs explained that they used a combination of chemotherapy and immunotherapy to prepare patients for the transplant and increase the chance of success. “We designed a regimen that balances low‑intensity chemotherapy with effective immunotherapy to prevent rejection,” he said. “We are the first to show that reduced‑intensity conditioning with cord blood can give reliable long‑term engraftment.”
Szabolcs also noted that the approach does not require a perfect immune match between donor and recipient. “That’s huge for ethnic minorities. Perfect matches are rare, but cord blood grafts can overcome this mismatch over a couple of months, allowing immunosuppressants to be tapered away.”
Early results
A total of 44 children were treated. After preparation, they received the cord blood stem cell transplant. Once the cells integrated, the children received a second, smaller infusion to help strengthen their immune system.
Most complications were mild. About 5 percent of children died from viral infections caused by immune suppression, a lower rate than in previous studies. Encouragingly, none of the children developed severe graft‑versus‑host disease.
Thirty children had metabolic disorders that prevented their bodies from removing harmful toxins, causing neurological decline. One year after treatment, all 30 had normal enzyme levels, and their neurological decline had stopped. Some even gained new skills.
Most children with metabolic disorders had leukodystrophies, which are usually fatal within a few years. With standard cord blood transplants, the three‑year survival rate is about 60 percent. In this trial, more than 90 percent were alive after three years.
Dr. Szabolcs says the approach offers advantages, including lower cost. “New technologies may help these diseases, but they may not be available to most centers. Our regimen is more robust, easier to apply, and significantly less expensive.”
The study was published in Blood Advances.