Hematopoietic stem cell transplantation

Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood, in order to replicate inside a patient and produce additional normal blood cells. HSCT may be autologous (the patient's own stem cells are used), syngeneic (stem cells from an identical twin), or allogeneic (stem cells from a donor).

It is most often performed for patients with certain cancers of the blood or bone marrow, such as multiple myeloma, leukemia, some types of lymphoma and immune deficiencies. In these cases, the recipient's immune system is usually suppressed with radiation or chemotherapy before the transplantation. Infection and graft-versus-host disease are major complications of allogeneic HSCT.

HSCT remains a dangerous procedure with many possible complications; it is reserved for patients with life-threatening diseases. As survival following the procedure has increased, its use has expanded beyond cancer to autoimmune diseases and hereditary skeletal dysplasias, notably malignant infantile osteopetrosis and mucopolysaccharidosis.

Medical uses

Indications

Indications for stem-cell transplantation are:

Malignant (cancerous)

Acute myeloid leukemia

Chronic myeloid leukemia

Acute lymphoblastic leukemia

Juvenile myelomonocytic leukemia

Hodgkin lymphoma (relapsed, refractory)

Non-Hodgkin lymphoma (relapsed, refractory)

Neuroblastoma

Ewing sarcoma

Multiple myeloma

Myelodysplastic syndromes

Gliomas, other solid tumors

Nonmalignant (noncancerous)

Thalassemia

Sickle cell anemia

Aplastic anemia

Fanconi anemia

Malignant infantile osteopetrosis

Mucopolysaccharidosis

Paroxysmal nocturnal hemoglobinuria

Pyruvate kinase deficiency

Immune deficiency syndromes

Autoimmune diseases, including multiple sclerosis

Many recipients of HSCTs are multiple myeloma or leukemia patients who would not benefit from prolonged treatment with, or are already resistant to, chemotherapy. Candidates for HSCTs include pediatric cases where the patient has an inborn defect such as severe combined immunodeficiency or congenital neutropenia with defective stem cells, and also children or adults with aplastic anemia who have lost their stem cells after birth. Other conditions treated with stem cell transplants include sickle cell disease, myelodysplastic syndrome, neuroblastoma, lymphoma, Ewing's sarcoma, desmoplastic small round cell tumor, chronic granulomatous disease, Hodgkin's disease and Wiskott–Aldrich syndrome. Non-myeloablative, so-called mini transplant (microtransplantation) procedures, have been developed requiring smaller doses of preparative chemotherapy and radiation therapy, allowing HSCT to be conducted in the elderly and other patients who would otherwise be considered too weak to withstand a conventional treatment regimen.