About 100,000 Americans live with sickle cell disease, an inherited blood disorder that mostly affects people of African, Hispanic, and Middle Eastern descent. Sickle cell disease is caused by abnormal changes in the red blood cells–or hemoglobin–that carry oxygen throughout the body. The changes are the result of a genetic condition, but stem cell treatment is being explored as a viable way to stop the ravaging effects of sickle cell disease.
The disorder alters the structure of red blood cells, turning them from their normally round shape into sickle-shaped cells that are stiff and sticky. The affected cells become less efficient at doing their oxygen-carrier job, causing severe pain, and sometimes leading to organ damage or stroke.
Stem cell treatment in children
Currently, there is no widely available, established cure for sickle cell disease. However, a number of children with the disease have been successfully treated with blood stem cell, or bone marrow, transplants. The treatment is known as HSCT, or hematopoietic stem cell transplant. The term hematopoietic means that the transplant helps the formation of (new) red blood cells.
Until recently, the transplant approach used in children was believed to be too risky for adults. It was thought that it could pose serious dangers due to the chemotherapy needed to destroy sick cells before their replacement. The side effects of chemotherapy and other medications used in the process was deemed too toxic for adults.
Modified treatment tested in adults
In 2014, a research team at the National Institutes of Health (NIH) published the results of a long-term study using a modified transplant procedure for adults.
Thirty patients, ages 16 to 65, with severe sickle cell disease participated in the study between 2004-2013. The patients first underwent a less toxic regimen to kill off some of their damaged blood cells. Using healthy hematopoietic stem cells donated by a brother or sister, study subjects underwent a so-called allogenic stem cell transplant into their bone marrow – where red blood cells are produced.
The team found that the stem cell transplant reversed the disease in 26 of 30 patients (87%). The patients developed normal red blood cells, required fewer hospitalizations, and less use of major painkillers. The patients were followed up with for over 3 years and didn’t experience graft-versus-host disease—a problematic immune response in which donor cells attack the recipient.
Until very recently, most patients had to take immunosuppressants – drugs used to help the body accept the transplanted cells – for several months or years after transplantation. These medications are powerful but carry severe side effects and may put the patient at risk of developing other diseases. New improvements to these drugs and further knowledge about the immune system are making HSCT more frequent and successful.
The results of the study hold promise for future HSCT treatments of adults with sickle cell disease.
If you have sickle cell disease or another blood disease, call us to learn more about stem cell treatment. Call National Stem Cell Centers in the New York office at (646) 448-0427, or our Long Island office at (516) 403-1457 to discuss a treatment option that is right for you.