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Questions about Transplant and Clinical Research
 

 
What are hematopoietic stem cells?

Hematopoietic stem cells are cells that reside in the bone marrow and produce blood cells such as red blood cells, white blood cells and platelets. There are several types of white blood cells including granulocytes, lymphocytes and monocytes.


What does transplantation mean?
Hematopoietic cell transplantation means strictly spoken the infusion of stem cells into a vene. The term transplantation is frequently used in broader context to describe administration of high-dose or intermediate-high-dose chemotherapy plus subsequent stem cell infusion. An ablative transplant is a transplant in which the preparative regimen is so aggressive that your bone marrow cannot recover without infusion of stem cells. A non-myeloablative transplant is a transplants in which the preparative regimen is more friendly and bone marrow recovery can occur to a certain degree without infusion of stem cells. 


How are stem cells for transplantation collected?
Stem cells can be collected from the bone marrow or from the blood by leukapheresis. During a harvest stem cells are distracted from the bone marrow of the sacral bone. The procedure occurs under (local) anesthesia. A bone marrow harvest contains stem cells and mature blood cells. Stem cells are separated from the other cells in the laboratory and are frozen for later use or prepared for infusion. A leukapheresis occurs by use of an apheresis machine. The procedure can be compared to a platelet donation procedure. A stem cell donor is connected to the machine and stem cells are distracted from blood that passes through the machine. Under normal circumstances few stem cells circulate in the blood. To make stem cell donation efficient stem cells should be mobilized from the bone marrow into the blood ; this may be done after chemotherapy treatment while you receive growth factor for recovery of the bone marrow if you donate your own cells (autologous), or during growth factor alone if a family member or unrelated person donates cells to you (allogeneic). 


Who can be a stem cell donor?
Two major donor categories can be distinguished: autologous and allogeneic. A patient donating his or her own stem cells for reinfusion at a later stage is called an autologous donor. A family member or unrelated person donating stem cells for infusion in a patient after ablative or non-myeloablative chemotherapy is called and allogeneic donor. Children and adults can be autologous or allogeneic donors of stem cells collected by bone marrow harvest or leukapheresis. About 25% of patients have a sibling donor; for 40 to 50% of Caucasians a matched unrelated donor can be found. Cord blood can be preserved for autologous or allogeneic transplant purpose. 


Which diseases can be treated by stem cell transplantation?
There are several disease categories that can be treated by stem cell transplantation.

Malignant diseases or cancer
Several malignant diseases can be treated by stem cell transplantation. The response to transplantation depends among others on the type of disease, the disease stage at transplant and prior treatment for cancer. Transplants can be part of the initial treatment or be administered at disease recurrence after initial other prior treatment. The response of cancer to transplantation is in general best early during the disease course, when cancer cells have not yet become resistant to chemotherapy.
 
 

Genetic diseases
Genetic diseases may be treated by infusion of stem cells from a healthy donor to restore the genetic defect to a percentage sufficient for normal body function. Transplants early during the disease course may prevent that irreversible damage of organs occurs as result from the defect. Genetic diseases that may benefit from transplantation include immune deficiency disorders, abnormalities of hemoglobulin, and abnormalities or deficiencies of enzymes including diseases called inborn errors of metabolism.
  

Bone marrow abnormalities
Bone marrow abnormalities such as aplasia or myelodysplasia may be cured by adequate preparative treatment and infusion of allogeneic hematopoietic stem cells to restore bone marrow capacity.

Autoimmune diseases
Autoimmune diseases may benefit from the therapeutic effect of chemotherapy and from correction of disfunction of the immune system by infusion of allogeneic immune competent cells.


What are the side effects of transplantation?

Infusion of stem cells does in general induce little or no side effects with appropriate prophylaxis and current procedures. Other side effect of transplantation are induced by the preparative regimen and by the fact whether the transplant is autologous or allogeneic.
Ask your doctor about side effects. The patient informed consent you receive when participating in a study explains the side effects that may occur.  


How can side effects be reduced?

1) To reduce side effects it is important that you are in good condition; at younger age you tolerate the same treatment better than at older age. It is a given fact that cannot be changed.
2)  Myeloablative or high-dose chemotherapy induces more side effects than non-myeloablative chemotherapy. Thus non-myeloablative transplants are preferable above myeloablative transplants. 


How effective are reduced intensity conditioning transplants?
It is likely that reduced intensity conditioning transplants are as effective as myeloablative transplants when the overall treatment is well planned and the disease is in complete remission before start of the non-myeloablative preparative regimen.


Is a clinical study the same as a clinical trial?                                Transplant Creations prefers to use the term study. Study and trial are though both used. From terminology perspective, a clinical study examines safety and efficacy of a product or treatment strategy, a trial tries to evaluate safety and efficacy. 


What does participation in clinical studies involve?
Participation in a clinical study means that you participate in an effort that enrolls patients and treats and evaluates according to the treatment strategy defined in a protocol. A protocol defines standards for treatment that will be applied to all patients treated according to that protocol. The results of treatment per protocol can be analyzed to determine the appropriateness of the treatment. When you are treated per protocol you generally participate in a clinical study.

Participation in clinical studies does not mean more visits or tests than standard in patient care. A study may require some specific tests, but these can occur during standard visits. Evaluation and visits are in Transplant Creations= protocols reduced to these necessary for treatment and do not exceed what should be the standard of care.  

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