Often used to treat blood diseases and certain types of cancer, the success rate of stem cell transplant depends on several factors including the type of disease and donor compatibility, tells Dr Anoop P, senior consultant, haematology, haemato-oncology, paediatric haemato-oncology and bone marrow transplant, Aster CMI Hospital, Bengaluru, in an interview with Rishita Khanna. Edited excerpts:
What is stem cell transplant?
Stem cell transplant, also known as bone marrow transplant, is a medical procedure in which damaged or diseased bone marrow is replaced with healthy stem cells. These are parts of the blood and immune system. Stem cell transplants are often used to treat many diseases, including lymphoma, leukaemia, multiple myeloma, haemoglobin disorders such as thalassemia, sickle cell anaemia, and bone marrow failure conditions such as aplastic anaemia. They have the ability to heal or provide long term relief by replacing damaged cells with healthy cells and restoring the body's ability to produce blood cells and fight diseases.
What are the primary types of stem cell transplants, and how do they differ in their application and effectiveness?
The main types of stem cell transplants are autologous and allogeneic. Autologous transplant uses the patient's own stem cells collected before treatment and has a lower risk of rejection, but is limited to the treatment of certain diseases. Allogeneic transplantation uses stem cells from a suitable alternative donor who is genetically matched with the patient. Although autologous transplantation is the first choice for some cancers such as multiple myeloma and lymphoma, allogeneic transplantation is preferred for leukemia, thalassemia, aplastic anaemia and immunodeficiency disorders. Both aim to replace damaged cells, but their effectiveness depends on factors such as the type of disease and donor compatibility.
How are stem cells harvested for transplantation and what is the criteria for selecting donors?
There are two methods of collecting stem cells – peripheral blood stem cell collection via apheresis, where blood is collected, stem cells are isolated, and the remaining blood is returned, or bone marrow aspiration, where stem cells are extracted from the pelvic bones with a needle. Donors undergo rigorous screening, including medical history, physical examination and blood tests to ensure compatibility and minimise complications. Compatibility is determined by human leukocyte antigen (HLA) matching, which evaluates tissue type compatibility between the donor and recipient. Donors must be healthy and committed to the donation process.
What are the diseases that benefit most from stem cell transplant, and what are the success rates?
Stem cell transplants are often used to treat many blood diseases and some cancers. However, the success rate depends on variables such as the subtype of the disease, the patient's age, general health status, and type of transplant.
What are the key challenges or risks for donors and recipients?
Stem cell transplantation carries risks and complications mainly for the recipients. It is generally a safe procedure for donors. Recipients may face complications such as transplant rejection, life threatening infections, organ damage from chemotherapy or radiation, and long-term effects such as reduced fertility or secondary cancer. Donors may experience discomfort or problems with stem cell collection procedures such as bone marrow aspiration or apheresis. Additionally, both parties may experience psychological stress, financial stress, and uncertainty about treatment.
What advice would you give to individuals considering stem cell transplantation?
Consult a haematologist, oncologist, or stem cell transplant specialist to evaluate whether it is appropriate for your situation. Discuss risks, cost-effectiveness, and treatment options.