Blood Stem-Cell Transplant Regimen Reverses Sickle Cell Disease in Adults
Previous blood stem-cell transplantation regimens using chemotherapy to completely destroy bone marrow have successfully cured children of sickle cell disease, but those regimens are too toxic for adults. This new simplified blood stem-cell transplant regimen, which does not use chemotherapy, has eliminated sickle cell disease in nine of 10 adults who were severely affected by the disease. This regimen will likely be applicable to other nonmalignant diseases and can be performed at most transplant centers.
Akinso: A blood stem-cell transplant regimen has effectively reversed sickle cell disease in adult patients according to a National Institutes of Health study.
Tisdale: What we did was to take an approach to bone marrow transplant that would allow us to do it in very sick adults.
Akinso: Dr. John Tisdale is the study’s principal investigator in the NIH Molecular and Clinical Hematology Branch.
Tisdale: This is a study where we were looking to see if we could fix, this disease, sickle cell disease by getting bone marrow stem cells — those are the seeds of the bone marrow that all the blood comes from, from a brother or sister who doesn't have the disease and administer those to the patient with the disease as a way to replace their red blood cell.
Akinso: The study was conducted by the National Institute of Diabetes and Digestive and Kidney Diseases, the National Heart, Lung and Blood Institute, and National Institute of Allergy and Infectious Diseases. Sickle Cell disease is caused by an altered gene that produces hemoglobin, the protein in normal red blood cells that carries oxygen throughout the body. Dr. Tisdale examines how the stem-cell transplant affects sickle cell disease.
Tisdale: Stem cells in the bone marrow are the source of blood, so all of the blood derives from stem cells. And these stem cells in the bone marrow make the red blood cells and carry the genetic defect. So if we can get stem cells from somebody else who doesn’t have the genetic defect and get them to grow in the patient then they will start making normal red blood cells and replace the defective red blood cells that cause the disease.
Akinso: Dr. Tisdale says given the results, this modified transplant regimen changes the equation for treating adult patients with sickle cell disease in a safer, more effective way.
Tisdale: We were hopeful that in doing this we could get a mix of both patient and donor cells making blood and get enough to replace the red blood cells of the donor. And in fact that is what we accomplished. So in 9 of the 10 patients that we transplanted, we have a mix of both the donor cells and the recipient cells and it’s enough to completely switch the red blood cells over to the donor type.
Akinso: Dr. Tisdale says that the patients have had a remarkable change in their lives. He added that this regimen will likely have broad application to other nonmalignant diseases and can be performed at most transplant centers. For more information on sickle cell disease and this discovery, visit www.niddk.nih.gov. This is Wally Akinso at the National Institutes of Health Bethesda Maryland.
About This Audio Report
Reporter: Wally Akinso
Sound Bite: Dr. John Tisdale
Topic: Stem Cell, Sickle Cell Disease