What are the Types of Stem Cell Transplants

Indian researchers recently identified several factors linked to improved survival among multiple myeloma patients who have undergone stem cell transplantation. These factors included albumin levels at diagnosis and the achievement of a response – particularly a complete response –after transplantation, says an article published The Myeloma Beacon in November 2012.

2 Types of Transplant

Stem cell transplant is today used in the world to treat more than 80 diseases including cancers such as lymphoma, leukaemia, neuroblastoma and more. These cells are most commonly derived from the three following sources: bone marrow, bloodstream and umbilical cord blood. There are mainly two types of transplant: Autologous and Allogeneic.

1. Autologous – This type of procedure mainly uses the person’s own stem cells. It is actively being used in treating various cancers. Most transplants for multiple myeloma and relapsed non-Hodgkin's or Hodgkin lymphoma are autologous, according to an article published in WebMD. Its use is coupled with high-density treatment such as chemotherapy and radiation. The cells are harvested from the patient’s body and frozen. Post the chemo or radiation, the harvested units are infused in the patient’s body in order to help the body rebuild its immune system. One of the major advantages of this therapy is that there is less risk of rejection or graft versus host diseases as the cells infused are the person’s own. However, its disadvantage is that the graft versus tumour effect may not be produced therefore it could be less effective in fighting the cancer. Autologous transplant can also been done with the help person’s own cord blood collected and frozen at the time of birth.
2. Allogeneic – Allogeneic transplant refers to the type of therapy that takes the stem cells from another person. The donor could be related or unrelated. Each person has a unique tissue type which is characterised by Human Leucocyte antigens (HLA). A donor must have a similar or identical HLA to the patient for the transplant to be successful. The better the match, the higher the rate of success. Identical twins have identical HLA while siblings have a similar one. Siblings carry a 25% chance to be perfect match. Also, umbilical cord blood from siblings could be used in this case. In case a match is not found with a relative, then you can look for an unrelated donor with a similar tissue type. Unlike, autologous transplant, there are higher chances of rejection and graft versus host diseases (donor cells attacking the patient’s body). But the upside is such a therapy is more successful in creating a graft versus cancer effect thereby minimizing the chances of a relapse.

Umbilical cord blood should be the preferred option as it is known to less likely develop graft versus host disease as well as carry blood-borne disease, says an article published in Leukaemia and Lymphoma society. It can be used both for autologous and allogeneic transplant.