bone marrow transplants have also been used in the treatment of hereditary blood conditions, including beta thalassemia, aplastic anemia, Fanconi anemia, and sickle cell anemia; however, due to the risks associated with this, this is rarely used unless the condition is fatal.
Thalassemia is a disorder commonly found in Mediterranean people and is of two types: alpha and beta. In beta thalassemia, the beta globulin chain is absent in the hemoglobin and it leads to severe lifelong anemia, requiring frequent transfusions and thus causes a poorer quality of life.
Sickle cell anemia is another hereditary condition where the glutamic acid is substituted by valine in the beta globulin chain of hemoglobin, and this leads to abnormal-shaped RBCs and the vaso-occlusive crises associated with the condition. The only known cure for sickle cell disease in children is HSC transplant, but due to the difficulty in finding an HLA match for donors, this is a rare treatment.
There have been successful BMTs in such patients, however the pool of possible HLA-matched donors is small, and there have been attempts to use induced pluripotent stem cells for the treatment of thalassemia and sickle cell anemia.
Lymphomas
Another blood cell tumor treated by stem cells is lymphomas, including Hodgkin’s lymphoma, multiple myeloma, and non-Hodgkin’s lymphoma.
Hodgkin’s lymphoma is a tumor of the lymphocytes characterized by Reed-Sternberg cells and is classified as two types: classical (nodular sclerosing, mixed cellularity, lymphocyte predominant, and lymphocyte depleted types) and the rare nodular lymphocyte-predominant disease. Advanced or relapsing Hodgkin’s lymphoma is treated by aggressive chemotherapy followed by stem cell replacement; it is usually preferred to utilize the patient’s own cells as compared to finding a donor.
Non-Hodgkin’s lymphomas usually are tumors of the B cells, rarely of T cells. Common B-cell tumors are diffuse large B cell lymphoma and follicular lymphoma. As with Hodgkin’s lymphomas, refractory or relapsed tumors are usually treated with autologous transplantation, however the adverse effects still run high with this treatment.
Multiple myeloma, a cancer of the antibody-producing plasma cells, leads to bone pain and fractures, anemia, infections, neurological impairment, and renal failure. Compared to the traditional treatment of chemotherapy being adopted over the years, new trials have shown the promise of autologous stem cell transplants following aggressive chemotherapy, the stem cell rescue treatment modality.
Autoimmune Disorders
In the late 1990s, stem cells were used in the treatment of patients with severe autoimmune diseases. Both myeloablative and non-myeloablative regimens have been tried prior to hematopoietic stem cell transplant (HSCT).
Patients with systemic sclerosis treated by autologous HSCT showed signs of better skin tightness and joint flexibility, along with some patients who exhibited a reversal of pulmonary alvelolitis.
Promising results have also been shown in patients with Crohn’s disease, where the immune system attacks microbial antigens leading to intestinal inflammation; autologous HSCT has shown to improve the condition considerably and improve quality of life.
Other autoimmune conditions that have been successfully treated by HSCT include systemic lupus erythematous (SLE) and rheumatoid arthritis.
Vascular Conditions
In recent years, many trials have indicated that injection of HSCs in a non-hematopoietic organ may improve the function by either cell fusion or differentiation. Stem cells obtained from the bone marrow or peripheral blood, or purified HSCs may facilitate in the repair following a myocardial infarction, an ischemic injury, or even peripheral vascular diseases due to atherosclerosis or Buerger’s disease.
Trials are also leaning in toward the regeneration of the liver by using stem cells in debilitating diseases like liver cirrhosis.
Others
An evolving utilization of HSCs is the treatment of unresectable tumors. HSCs extracted from peripheral and cord blood have been shown to have antitumor activity against breast cancer cells and leukemia. Researchers have found this to be a possible treatment modality in patients with metastatic renal carcinomas.
Autologous stem cell transplants were also conducted in patients with diabetes mellitus type 1, and showed significant improvement by increasing C-peptide levels and decreasing the insulin requirement. To date, this is the only treatment shown to cure this condition in humans.
Conclusion
Hematopoietic stem cells have altered the course and treatment of many diseases that were deemed fatal. Further studies into the use of these stem cells to regenerate damaged organs and improve organ function will lead to a new era of many chronic, debilitating diseases being cured.
There are still many unchartered territories in the research of these multipotent cells, and aggressive trials and research continue to unravel the extent to which hematopoietic stem cells can be used to regenerate diseased human organs and tissues.
Reja Syed Emran
Independent Scholar
See Also: Blood Adult Stem Cell: Development and Regeneration Potential; Blood Adult Stem Cell: Existing or Potential Regenerative Medicine Strategies.
Further Readings
“Aetos Kaukasios.” www.theoi.com/Ther/AetosKaukasios.html (Accessed May 2012).
Appelbaum, F. R. (2012). “E. Donnall Thomas (1920–2012).” Science, v.338/6111 (2012).
Attal, M., J. L. Harousseau, A. M. Stoppa, et al. “A Prospective, Randomized Trial of Autologous Bone Marrow Transplantation and Chemotherapy in Multiple Myeloma.” New England Journal of Medicine, v.335 (1996).
Burt, Richard K., et al. “Clinical Applications of Blood-Derived and Marrow-Derived Stem Cells for Nonmalignant Diseases.” JAMA, v.299/8 (2008).
Childs, R., A. Chernoff, N. Contentin, and E. Bahceci. “Regression of Metastatic Renal-Cell Carcinoma After Nonmyeloablative Allogeneic Peripheral-Blood Stem-Cell Transplantation.” New England Journal of Medicine, v.343 (2000).
Copelan, E. A. “Hematopoietic Stem-Cell Transplantation.” New England Journal of Medicine, v.354/17 (2006).
Couri, C. B., M. B. Oliveira, A. L. Stracieri, et al. “C-Peptide Levels and Insulin Independence Following Autologous Nonmyeloablative Hematopoietic Stem Cell Transplantation in Newly Diagnosed Type 1 Diabetes Mellitus.” JAMA, v.301/15 (2009).
Cutler, C. and J. H. Antin. “Peripheral Blood Stem Cells for Allogeneic Transplantation: A Review.” Stem Cells, v.19 (2001).
Giardini, C. and G. Lucarelli. “Bone Marrow Transplantation for Beta-Thalassemia.” Hematology/Oncology Clinics of North America, v.13/5 (1999).
Gluckman, E., A. Devergié, H. Bourdeau-Esperou, et
