Less Toxic Transplant Treatment for Sickle Cell
Technique avoids ill effects related to long-term use of anti-rejection drugs, study says
The current study used cells from siblings that were a match to the patient's cells. A new study, however, is underway that will test whether half-match cells from a parent will work as well, Tisdale said.
"This way we would be able to reach nearly every patient with sickle cell disease," he said.
Sickle cell disease is a serious disorder in which the body makes crescent-shaped red blood cells.
Normal red blood cells are disc-shaped and move easily through the blood vessels. They contain an iron-rich protein called hemoglobin, which carries oxygen from the lungs to the rest of the body.
Sickle cells have abnormal hemoglobin and are stiff and sticky, blocking blood flow in the limbs and organs, causing relentless pain and organ damage. Infection risk is also increased.
Current treatment for sickle cell disease includes medication for pain and a drug (hydroxyurea) that helps normalize hemoglobin. Patients may also need blood transfusions as the disease worsens.
For the study, Tisdale's team enrolled 30 patients, 16 to 65 years old, with severe sickle cell disease. Between 2004 and 2013, patients were given partial stem cell transplants with cells from a brother or sister.
Findings on the first 10 patients were reported in 2009, with nine of them successfully treated.
Of the remaining patients, 15 stopped taking anti-rejection medication one year after transplant and still had not had rejection or graft-versus-host disease during a median follow-up of roughly 3.4 years, the investigators found.
Overall, the partial transplant reversed the disease in 26 of 30 patients, the researchers said
The advantage of this procedure is that it gets people off drugs that weaken the immune system and cause side effects such as infection and joint swelling. Generally, transplants that don't use matched donors require patients to take these drugs for the rest of their lives, the researchers noted.