Key points
- A blood stem cell transplant (often called a "bone marrow transplant") replaces the blood-making cells after high-dose chemotherapy or radiotherapy, and is used mostly in blood cancers such as leukaemia, lymphoma, multiple myeloma and myelodysplastic syndromes [1].
- In an autologous transplant the cells come from the patient themselves, and in an allogeneic transplant from a donor; the donor can be a matched brother or sister, an unrelated person, a half-matched family member or cord blood [1, 2].
- In an allogeneic transplant, the donor's immune cells can destroy remaining cancer cells (the "graft-versus-leukaemia" effect), but they may also attack the patient's skin, liver, gut and other organs; this complication is called graft-versus-host disease (GVHD) [1].
- Today most cells are collected from the blood with an apheresis machine; giving the cells to the patient involves no surgery, is like a blood transfusion and takes 1 to 5 hours [1, 3].
- The whole transplant journey takes several months; even after blood counts are back to normal, full recovery of the immune system takes several months after an autologous transplant and 1 to 2 years after an allogeneic transplant [1].
- During the transplant period, a temperature of 38 °C or higher, shivering, bleeding, severe diarrhoea, a new skin rash or yellowing of the eyes means you need to contact the transplant centre straight away [4, 5, 6].
What is a blood stem cell transplant?
Blood-forming (haematopoietic) stem cells are immature cells in the bone marrow that develop into the three main types of blood cell: white blood cells, which fight infection, red blood cells, which carry oxygen to the tissues, and platelets, which help stop bleeding [1].
Very high-dose chemotherapy or radiotherapy can destroy more cancer cells, but it also destroys the blood-forming cells of the bone marrow. A stem cell transplant solves this problem: after the intensive treatment, healthy cells are infused into a vein, find their own way to the bone marrow and start making blood again [1].
These cells can be obtained from the blood (the commonest method), from the bone marrow or from a newborn baby's umbilical cord blood; the transplant is usually named after this source: peripheral blood stem cell transplant, bone marrow transplant or cord blood transplant [1]. A transplant usually does not fight the cancer directly; instead, it makes it possible to rebuild blood production after intensive treatment. The important exception is the "graft-versus-leukaemia" immune effect in an allogeneic transplant [1].
| Feature | Autologous transplant (the patient's own cells) | Allogeneic transplant (donor cells) |
|---|---|---|
| Source of the cells | The patient; the cells are collected and frozen before high-dose treatment [3] | A matched brother or sister, an unrelated donor, a half-matched family member or cord blood [1, 2] |
| Why it is done | Makes high-dose chemotherapy possible and restores blood production afterwards [1] | Replaces the patient's bone marrow, with the added immune effect of the donor cells against the cancer [1] |
| Examples of standard uses | Multiple myeloma as first-line treatment; relapsed Hodgkin lymphoma that has responded to chemotherapy [2] | Acute myeloid leukaemia with intermediate or adverse risk in first remission; high-risk acute lymphoblastic leukaemia; high-risk myelodysplastic syndrome [2] |
| Graft-versus-host disease (GVHD) | Does not occur, because the cells are the patient's own [1] | May occur; preventive medicines and close follow-up are needed [1] |
| Particular concern | A small chance of putting cancer cells back along with the collected cells [1] | GVHD and infections, because the immune system is suppressed for longer [1, 7] |
| Full recovery of the immune system | Several months [1] | 1 to 2 years [1] |
A "syngeneic" transplant (from an identical twin) is rare. A "mini-transplant" is a type of allogeneic transplant with lower-dose treatment, and in a "tandem transplant" two autologous transplants are done a few weeks to a few months apart [1].
Who needs a transplant?
A transplant is used mostly for blood cancers such as leukaemia, lymphoma, multiple myeloma and myelodysplastic syndromes. It is also used in some solid tumours, such as neuroblastoma, Ewing sarcoma, relapsed brain tumours in children and germ cell tumours (including testicular cancer), and in conditions such as aplastic anaemia, sickle cell disease and some autoimmune diseases [1].
International transplant societies, including the European Society for Blood and Marrow Transplantation (EBMT) and the American Society for Transplantation and Cellular Therapy (ASTCT), update the uses of transplant based on the evidence, and for each disease and stage they classify a transplant as "standard", a "clinical option", "developmental" (still being researched) or "generally not recommended" [2, 8]. A few examples from the 2022 European guideline [2]:
- Multiple myeloma: an autologous transplant as first-line treatment for newly diagnosed patients is still standard.
- Acute myeloid leukaemia: an allogeneic transplant in first remission is recommended for intermediate-risk and adverse-risk disease, but not for favourable-risk disease.
- Acute lymphoblastic leukaemia: an allogeneic transplant is standard for high-risk disease (based on genetic abnormalities, response to treatment and measurable residual disease) and when the disease comes back.
- Lymphoma: in relapsed Hodgkin lymphoma that has responded to salvage treatment, an autologous transplant is standard; in large B-cell lymphoma that comes back early (less than 12 months after the first treatment), CAR-T cell therapy has taken the place of an autologous transplant, but when it comes back later and has responded to chemotherapy, an autologous transplant is still standard.
The decision to have a transplant and the choice of type depend on the type and stage of the cancer, whether the patient's own cells can be used, whether a matched donor is available, whether other effective treatments exist, the ability to tolerate high-dose treatment, other illnesses and previous treatments, and should be discussed with the transplant team [1].
The transplant journey, step by step
The main stages of a stem cell transplant
- 1
Assessment and counselling before the transplant
The function of the heart, lungs, liver and kidneys, other illnesses, hidden infections and the health of the mouth and teeth are checked to judge the risk of the transplant; the plan for the patient's companion (carer) is also settled at this stage [7, 9, 10]. Details are in the guide to the stages of a transplant.
- 2
- 3
Collecting the stem cells
After a few days of injections of a medicine that moves stem cells into the blood, the cells are collected with an apheresis machine over 4 to 6 hours and frozen; sometimes the cells are instead taken from the hip bone under general anaesthetic [3].
- 4
The conditioning regimen
High-dose chemotherapy and sometimes radiotherapy, usually lasting one to two weeks, is given to destroy cancer cells; in an allogeneic transplant this treatment also suppresses the patient's immune system so that the donor cells are not rejected [1].
- 5
Day zero: infusing the cells
After a few days' rest, the cells are given through an IV catheter, like a blood transfusion; this takes 1 to 5 hours, and the day of the infusion is called "day zero" [1].
- 6
Low blood counts and engraftment
Until the new cells start making blood, blood cells and platelets are very low and the risk of infection and bleeding is high; blood counts are checked regularly [1]. For example, in transplants using the patient's own cells in myeloma, white blood cells usually came back about 12 days after the infusion [11]. The complications of this period are covered in the guide to complications during the transplant.
- 7
Discharge and close follow-up
After discharge you usually visit the centre two or three times a week for tests, transfusions or topping up body salts (electrolytes). After an allogeneic transplant, if you have no complications, you can go back home about 100 days after the cells are infused, but follow-up with a doctor experienced in transplants continues [1].
Transplant guides for patients and families
Guides in this section
The stages of a transplant: from getting ready to the transplant
Assessment before the transplant, the donor and HLA matching, collecting the cells, the catheter, the conditioning regimen, the day of infusion, engraftment and the family's role. Read the guide
Complications during the transplant on the transplant unit
Nausea and mouth sores, fever and infection, bleeding, veno-occlusive disease of the liver (VOD/SOS), engraftment syndrome, acute GVHD and complications of CAR-T. Read the guide
After leaving the transplant unit: care at home
Preventing infection and food safety, catheter care, medicines, CMV monitoring, the schedule of visits, re-vaccination and warning signs. Read the guide
Long-term and chronic effects after a transplant
Chronic GVHD and its treatments, late effects on the hormone glands, bones, eyes, heart and kidneys, second cancers and the long-term screening plan. Read the guide
Specialist education for physicians
Subspecialist-level lessons on stem cell transplantation, haematology and oncology for physicians. Go to the education section
Other related guides: low blood counts and preventing infection, mouth sores, nausea and vomiting, nutrition during treatment and fertility and sexual health.
When should I get urgent medical help?
If at any stage of the transplant (before admission, during your hospital stay or after discharge) you have any of these symptoms, tell the transplant team straight away or go to an emergency department:
- A temperature of 38 °C or higher, shivering, a cough or sore throat, or redness and swelling at the catheter site; call your doctor before taking fever medicine [4].
- Bleeding that does not stop after a few minutes, bleeding from the mouth or nose, red urine, black or bloody stools, or a severe headache and confusion [5].
- A new skin rash, heavy or bloody diarrhoea, severe tummy pain or yellowing of the skin and eyes; these can be signs of acute GVHD [6].
- Rapid weight gain, a swollen tummy or pain in the upper right part of the tummy in the first weeks after the transplant [12].
- Pain in the upper left part of the tummy or pain in the left shoulder, or breathlessness on the days you are having injections of the medicine that stimulates stem cells [13].
- After CAR-T cell therapy: fever, confusion, severe drowsiness or difficulty speaking [14].
Frequently asked questions
Do they operate on the bone for a bone marrow transplant?
No. In most transplants the stem cells are collected from the blood: after a few days of injections of a stimulating medicine, blood flows through a vein or catheter into an apheresis machine, the stem cells are separated and the rest of the blood is returned to the body [3]. When the cells are taken from the bone marrow, this is done with a needle from the hip bone under general anaesthetic and takes about one to one and a half hours [3]. Giving the cells to the patient is also like a blood transfusion [1].
Who can be a donor?
How well a donor matches is measured by tissue markers called HLA, and the closer the match, the more likely the cells are to be accepted; the best donor is usually a matched brother or sister [1]. An international guideline estimates that about 25 to 30 percent of patients have a fully matched brother or sister [7]. Otherwise, an unrelated donor from a donor registry, a half-matched family member (a haploidentical transplant, often with the medicine cyclophosphamide given after the transplant to prevent GVHD) or cord blood is considered [2].
Is donating stem cells dangerous for the donor?
The side effects of donating are usually temporary. The stimulating medicine may cause flu-like symptoms, bone and muscle pain, headache and tiredness, which usually go away 2 to 3 days after the last dose; during apheresis there may also be light-headedness, shivering, numbness around the lips or cramps in the hands [3]. In bone marrow donation, the main risk is from the anaesthetic, and the collection site is sore for a few days; most donors are back to normal within a few days to a few weeks [3].
How long does a transplant take, and how long will I stay in hospital?
The whole transplant process takes several months: the conditioning regimen lasts one to two weeks, followed by the infusion of the cells and the recovery period [1]. How long you stay in hospital depends on the type of transplant and on complications; in one study, patients usually stayed in hospital for about 3 weeks [15]. After an allogeneic transplant you usually need to stay near the transplant centre for about 100 days [1].
Does a transplant cure cancer for certain?
The result of a transplant depends on the type and stage of the disease, the response to previous treatments and the patient's general health [1]. For example, in high-risk myelodysplastic syndrome an allogeneic transplant is an option with a chance of cure, and in chronic myelomonocytic leukaemia it is considered the only potentially curative treatment; in multiple myeloma, an autologous transplant is part of standard treatment, but in most patients the disease comes back over time afterwards [2]. It is best to talk specifically with your transplant doctor about what to expect and the chances of success.
Is CAR-T cell therapy also a kind of transplant?
CAR-T is not a stem cell transplant; in this treatment the patient's own T lymphocytes are collected, engineered in the laboratory to recognise cancer cells and multiplied, and then returned to the patient in a single infusion; this process takes about 3 to 5 weeks [14]. Its particular side effects, cytokine release syndrome and neurological side effects, are explained in the guide to complications during the transplant [14].
References
15 referencesShow all referencesClose the reference list
Numbers in the text, such as [1], refer to these sources. Sources with a “Study card” button are summarised in the site’s evidence library.
- 1
- 2
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- 5
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- 7
- 8Indications for Hematopoietic Cell Transplantation and Immune Effector Cell Therapy: Guidelines from the American Society for Transplantation and Cellular Therapy
- 9Multi-centre validation of the prognostic value of the haematopoietic cell transplantation-specific comorbidity index among recipient of allogeneic haematopoietic cell transplantation
- 10A scoping review of caregiver burden during allogeneic HSCT: lessons learned and future directions
- 11EVOMELA (melphalan) for injection, for intravenous use — Prescribing Information
- 12Revised diagnosis and severity criteria for sinusoidal obstruction syndrome/veno-occlusive disease in adult patients: a new classification from the European Society for Blood and Marrow Transplantation
- 13NEUPOGEN (filgrastim) injection, for subcutaneous or intravenous use — Prescribing Information
- 14
- 15Effect of Inpatient Palliative Care on Quality of Life 2 Weeks After Hematopoietic Stem Cell Transplantation: A Randomized Clinical Trial
This page is based on reputable scientific sources and was last updated on 28 October 2026. The content of this website is for educational and informational purposes only and does not replace consultation, diagnosis or treatment by a specialist physician. Consult your treating physician about any treatment decision.
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