Sickle cell disease, also known as sickle-cell anemia, is the most prevalent form of inherited blood disorder in the U.S. affecting more than 90,000 individuals.
The condition, which is characterized by the body producing sickle-shaped e.g. crescent-shaped red blood cells, is associated with elevated risks for bacterial infections, stroke, renal failure and other potentially fatal complications resulting in reduced life expectancy in individuals with the condition.
A new bone marrow technique, however, shows promise in treating individuals with sickle cell disease. For a study published in the journal JAMA on July 1, John Tisdale, from the National Institutes of Health, and colleagues assessed the efficacy and safety of a modified version of bone marrow transplant that mixes the stem cells from a healthy brother or sister of a patient with his own cells. The technique is a modified version of bone marrow transplant that works in young patients with severe sickle cell disease but doctors avoid using on adult patients because of its toxicity.
The researchers recruited 30 patients between 16 and 65 years old to participate in the non-myeloablative transplant study conducted from July 16, 2004 to October 25, 2013 and reported that 15 of the 30 patients that were provided with the experimental treatment stopped using anti-rejection drug a year after the transplant and avoided the common side effects of transplants such as rejection or the donor cells attacking the recipient's cells, a condition known as graft-vs-host disease, in a median follow-up of about 3.4 years.
"Engrafted patients continued to be disease-free and without graft-vs-host disease," Tisdale and colleagues wrote. "The majority of engrafted patients no longer taking immunosuppression medication had continued stable chimerism and disease reversion without graft-vs-host disease, suggesting tolerance to donor cells."
The researchers likewise said that while one of the patients died because of disease-related complications, the partial transplant has reversed the sickle disease in 26 of the 30 study participants.
One advantage of the procedure is that it gets to stop patients from taking drugs that could eventually weaken their immune system and cause unwanted side effects such the swelling of the joints and infection. Conventional transplants that do not involve match donors require the patients to take drugs for the rest of their lives.
"Side effects caused by immunosuppressants can endanger patients already weakened by years of organ damage from sickle cell disease," Tisdale said. "Not having to permanently rely on this medication, along with use of the relatively less-toxic partial stem-cell transplant, means that even older patients and those with severe sickle cell disease may be able to reverse their condition."
