How is Bone Marrow Transplant Done & Who Needs It?

A bone marrow transplant is a medical procedure where damaged or diseased bone marrow is replaced with healthy stem cells. The cells are taken from the patient's own body or a donor. It begins with conditioning therapy using high-dose chemotherapy or radiation to destroy abnormal cells and suppress the immune system. It is followed by the infusion of healthy stem cells through a central line.  

Bone marrow transplant is advised for blood cancer patients (leukaemia and lymphoma) or other blood disorders like aplastic anaemia, or genetic diseases that affect bone marrow function. 

Why is a bone marrow transplant needed? 

In leukaemia or aplastic anaemia, the diseased marrow fails to do its basic task of producing functional blood cells. A bone marrow transplant replaces it with healthy marrow so that the body produces enough blood cells. Sometimes, the procedure is necessary to correct underlying genetic defects like adrenoleukodystrophy, as it prevents further organ damage.  

What are the different types of bone marrow transplants? 

Here are a few types of bone marrow transplants you must know about:  

Autologous transplant: 

Uses the patient's stem cells collected and reintroduced after treatment to restore marrow function. 

Allogeneic transplant: 

Uses stem cells from a genetically matched donor (someone from the family) to replace the diseased marrow. 

Haploidentical transplant: 

Uses stem cells from a parent who is a half-match. 

Matched unrelated donor (MUD) transplant: 

Uses stem cells from an unrelated but HLA-matched donor identified through registries. 

Umbilical cord blood transplant: 

Uses stem cells collected from umbilical cord blood after birth. It is good for quick differentiation. 

How are a donor and a recipient matched? 

Donor-recipient matching is a meticulous process centred on human leukocyte antigen (HLA) typing. These antigens dictate immune compatibility, and minor mismatches can affect graft survival.  

Siblings hold the highest probability, which is a 25% chance of being a full match. Parents and children share only half of their HLA. The closer the match, the greater the chance of engraftment and the lower the risk of graft rejection or graft-versus-host disease (GVHD).  

Preparing for a Bone Marrow Transplant 

A bone marrow transplant is a serious surgery, and there are a few preparations that need to be done:  

• Evaluation tests of organs, infection risk, and general health assessments are done before transplant eligibility is confirmed. 
• Central venous catheter placement involves inserting a central line into a chest or neck vein to deliver stem cells, medicines, and blood products. 
• Growth factors are administered to mobilise stem cells into the bloodstream for collection in autologous transplants. 

Bone Marrow Transplant Procedure 

The bone marrow transplant procedure happens in a sequence of critical stages. Its complexity is necessary to ensure engraftment success and long-term survival. Let’s understand in detail: 

Conditioning therapy: 

Patients first undergo a conditioning regimen of high-dose chemotherapy and radiation therapy. This phase lasts 5-10 days, depending on the disease, patient age, and transplant type. Its purpose is to eradicate cancerous cells, suppress the immune system to prevent rejection, and create space within the marrow for new cells to settle. 

Side effects of conditioning include nausea, vomiting, diarrhoea, mouth sores, hair loss, fatigue, bleeding risks, and organ toxicities affecting the heart, liver, kidneys, or lungs. Reduced-intensity conditioning can be used in older patients or those with comorbidities to lessen toxicity while allowing engraftment. 

Stem cell infusion: 

On transplant day, fresh stem cells are infused intravenously through the central venous catheter. The infusion itself is painless and lasts from minutes to hours, depending on the cell volume. Patients are awake and monitored for any infusion reactions like fever, chills, or allergic symptoms. The infused cells circulate, migrating to the bone marrow niches, where they begin the engraftment process. 

Engraftment phase: 

After the infusion, the donor stem cells start producing new blood cells. Engraftment is achieved within two to four weeks. The change is visible when there is a rise in the platelet count. 

During this period, patients are at a high risk of infections and bleeding. They require protective isolation, broad-spectrum antibiotics, antifungals, and transfusion support. 

Daily blood counts, electrolyte monitoring, and infection surveillance continue rigorously until stabilisation. 

Post-engraftment monitoring and immunosuppression: 

For allogeneic transplants, immunosuppressive drugs are administered to prevent graft-versus-host disease. Doses and combinations vary based on protocols and individual reactions. Immunity is compromised for months to years. Hence, there is a need for strict infection control, dietary precautions, and gradual reintroduction to community exposures. 

This procedure demands multidisciplinary coordination with haematologists, transplant nurses, dietitians, physiotherapists, and psychosocial support teams. 

Bone Marrow Transplant Recovery 

The recovery time after a bone marrow transplant depends on the complexity of the transplant. Engraftment usually happens within two to four weeks, marked by rising blood counts. Until then, patients are highly susceptible to infections and bleeding. Hospital stays vary, but prolonged isolation, transfusion support, and infection surveillance are a part of the recovery process. 

Even after discharge, immune recovery can be incomplete for months to years. Regular monitoring, preventive antimicrobials, and dietary adjustments become a part of your daily life. Dietitians advise avoiding raw foods and potential contaminants, alongside general nutrition support to promote healing. Physical activity is gradually reintroduced to improve muscle strength, bone health, and cardiovascular endurance. 

Risks of Bone Marrow Transplants 

Immediate risks: 

Bleeding, infections, low blood cell counts, fever, allergic infusion reactions, and electrolyte imbalances due to intensive therapies. 

Organ complications: 

Cardiac failure, liver toxicity, kidney injury, and lung complications such as interstitial pneumonitis or pulmonary fibrosis. 

Fertility issues: 

Chemotherapy and radiation can impair fertility permanently in men and women. 

Graft-versus-host disease (GVHD): 

In allogeneic transplants, donor immune cells may attack recipient tissues, affecting skin, liver, gastrointestinal tract, eyes, and other organs. Acute GVHD occurs within weeks, while chronic GVHD can happen in months or years later. 

Neurological complications: 

Seizures, neuropathy, or cognitive changes due to conditioning toxicity. 

Metabolic and endocrine issues: 

Thyroid dysfunction, diabetes, or premature menopause in female patients. 

Musculoskeletal complications: 

Bone density loss leading to osteoporosis or fractures over time. 

Final Thoughts 

Bone marrow transplant is a lifesaving therapy for patients with complex haematological conditions. While it carries significant risks, advances in donor matching, conditioning protocols, supportive care, and long-term monitoring continue to improve success rates and quality of life post-transplant. If you or a loved one is exploring bone marrow transplant as part of their treatment, book a consultation today with our experienced doctors at Hinduja Hospital, Mahim, to understand your options and take a step towards better health. 

FAQs 

How painful is a bone marrow transplant? 

The transplant infusion itself is painless, like a blood transfusion, and you remain awake during the procedure. 

What is the process of a bone marrow transplant? 

After chemotherapy and/or radiation, stem cells are infused through a central line into your bloodstream without surgery. 

What happens to the donor of bone marrow? 

Donors have mild pain or fatigue, but their body replaces the donated marrow within 4 to 6 weeks. 

How many hours is a bone marrow transplant? 

The bone marrow transplant takes about one to two hours and is done through a central line without any pain.