Types of Transplants & Diseases Transplanted

Umbilical Cord Blood Transplantation Umbilical cord blood transplantation is a promising alternative to transplantation of hematopoietic stem cells more

In a bone marrow or peripheral blood stem cell transplant hematopoietic (blood forming) stem cells -- the immature or parent blood cells that give rise to all the types of mature blood cells -- are infused into the blood stream. The transplanted cells may have previously been collected from the patient or alternatively from a stem cell donor. Patients first undergo a preparative (also known as conditioning) regimen consisting of either chemotherapy or a combination of chemotherapy and radiation. The preparative regimen kills cancer cells but may also destroy normal cells in the bone marrow causing the blood counts to drop. Therefore, after the completion of this treatment, physicians infuse blood or marrow stem cells into the patient's bloodstream, just like a blood transfusion, using an intravenous catheter. No surgery is required. Over the following days the stem cells travel to the bone marrow space inside the bones, and within weeks begin to produce the cells needed for blood count recovery. For patients with certain forms of cancer, specific genetic diseases, and other types of blood disorders, a blood or marrow stem cell transplant is a promising form of treatment. For most patients, the aim is to cure their disease.

• Autologous Transplant

  In an autologous transplant, the patient's own stem cells are collected prior to high dose chemotherapy. Stem cells normally present in the bone marrow are stimulated to enter and circulate in the blood stream after treatment of the patient with growth factor. The cells, known as peripheral blood stem cells or PBSC, are then collected during a process called pheresis (where the blood is filtered through a machine in an outpatient clinic) and frozen in preparation for later use. Physicians next administer high doses of chemotherapy and / or radiation to kill the patient's cancer and then re-infuse the patient with their own blood forming stem cells.

• Allogeneic Transplant

  In an allogeneic transplant, the transplanted stem cells are from the bone marrow or blood stream of another person. This donor may be a related or unrelated volunteer, or a healthy newborn. In this type of transplant, physicians may give high doses of chemotherapy and/or radiation, reduced doses or even low doses of chemotherapy and radiation prior to transplant. Unlike an autologous transplant, the patient is given healthy stem cells from the donor that have no chance of containing tumor cells. Also, the new immune system cells of the donor can target and destroy cancer cells that have survived the chemotherapy and radiation given during the conditioning. This is beneficial and is called the graft-versus-malignancy effect. However, unlike autologous transplant, allogeneic transplant has the risks of rejection of the transplanted cells as well as a complication known as graft-versus-host disease (GvHD), where the transplanted donor immune system cells recognize the patient's body as foreign and causes disease.

Certain cancers are both sensitive to and require high doses of chemotherapy or radiation for effective therapy. These can be treated with either an autologous or allogeneic transplant with high dose conditioning. Patients with other types of cancers may be better treated with lower doses of chemotherapy and an allogeneic transplant. Transplant physicians will determine which transplant is the best for each diagnosis.

Diseases Treated with Transplantation

Depending on a patient's particular disease and the remission status of that disease, either an allogeneic or autologous transplant may be more effective. In some cases, if a patient relapses after an autologous transplant, a second transplant using a donor (allogeneic) may be performed.

Diagnosis	Allogeneic Transplant/ Autologous Rescue
Amegakaryocytosis/Congenital Thrombocytopenia	Allogeneic
Amyloidosis	Autologous
Aplastic Anemia/Refractory Anemia	Allogeneic
Germ Cell Tumors (Testicular Cancer)	Autologous
Paroxysmal Nocturnal Hemoglobinuria	Allogeneic
Hodgkin's Disease	Autologous or Allogeneic
Acute Leukemias	Allogeneic
Chronic Lymphocytic Leukemia	Allogeneic
Familial Erythrophagocytic Lymphohistiocytosis	Allogeneic
Non-Hodgkin's Lymphoma	Autologous or Allogeneic
Multiple Myeloma	Autologous or Allogeneic
Osteopetrosis	Allogeneic
Myelodysplastic Syndrome/Other Myelodysplastic Disorders	Allogeneic
Solid Tumors	Autologous
Wiskott-Aldrich Syndrome	Allogeneic

Types of Allogeneic Transplants

• Unmodified Transplants

  In an unmodified or conventional transplant, all of the marrow or blood stem cells (including the immune system cells called T cells) are infused into the patient without any manipulation in the laboratory. These transplants are more appropriate for patients at a higher risk of relapse and who can tolerate the medications required to prevent the complication known as graft-versus-host disease (GvHD). Memorial Sloan-Kettering physicians are investigating new medications to prevent and treat GvHD after unmodified transplants.

• T Cell-Depleted Transplants

  In T cell depleted transplants, a portion of the T cells (the cells that cause GvHD) are removed in the laboratory before the stem cells are infused into the patient. The rationale for this treatment is that new T cells that develop within the patient are less likely to cause GvHD but can still lead to immune system recovery. This is in contrast to T cells that are already formed in the donor (as are delivered in a conventional transplant) which are more likely to cause GvHD when transplanted.

  Because T cell depleted transplants have a lower risk of GvHD, they can allow transplant between patients and donors whose tissue types (known as 'HLA') are not fully matched. Furthermore, because this type of transplant can be easier to tolerate, it may be available to older patients, even those over 60 years old provided they are otherwise medically fit. Memorial Sloan-Kettering physicians are investigating the addition of new agents such as KGF and IL-7 to speed the recovery of the immune system after T cell depleted transplants.

• Cord Blood Transplants

  Another potential source of stem cells is cord blood. This is blood collected from the umbilical cord and placenta of healthy newborns. Cord blood has a number of advantages over unrelated volunteer donor stem cells. Firstly, cord blood is already collected and frozen in cord blood banks around the world. Therefore, it is much more rapidly available than stem cell collections from adult unrelated volunteers. Second, due to the naïve immune system of the newborn donor, the likelihood of graft-versus-host-disease (GvHD) after cord blood transplant is low, and therefore there is a decreased requirement for a very close tissue type (HLA) match between the patient and the newborn donor. This means cord blood can be a good alternative stem cell source for patients without a matched unrelated volunteer, particularly for those patients requiring conventional (non T cell depleted) transplants. Memorial Sloan-Kettering physicians have shown cord blood can extend transplant access to racial and ethnic minorities or patients with mixed ancestry. However, ensuring an adequate cell dose, especially for larger children and adult patients, is a very important determinant of transplant success. Therefore, Memorial Sloan-Kettering physicians frequently combine two cord blood units in a double unit transplant to increase the number of cord blood cells given on transplant day. Cord blood transplants are performed after high dose (myeloablative), reduced intensity, or non-myeloablative (mini) conditioning regimens.

• Reduced Intensity or Non-Myeloablative (Mini) Transplants

  Memorial Sloan-Kettering physicians use "reduced intensity" or "non-myeloablative" transplants for selected patients with leukemia, non-Hodgkin's lymphoma, Hodgkin's disease, and multiple myeloma. These transplants involve lower doses of chemotherapy and radiation and therefore may be better tolerated than traditional transplants involving high dose conditioning. Therefore, they can be safer than high dose chemotherapy and radiation and may be more suitable for patients that have had extensive prior treatment, who are older, or who have other medical problems.

• Donor Lymphocyte Infusions (DLI)

  For patients with certain types of cancer whose diseases recur late after transplantation, physicians may treat the patient with gradually increasing numbers of T cells from the original donor. The low levels of T cells can eliminate the recurrent cancer without causing significant GvHD. Memorial Sloan-Kettering researchers have conducted studies to establish a schedule of tolerable, escalating doses of donor white blood cells in relapsed patients.