How are blood stem cells infused during a Haematopoietic Stem Cell Transplantation?

The process of infusion of stem cells is a significantly life-changing moment for patients and their families. We are often asked about how we reinfuse blood stem cells into patients during the transplant procedure.

It is a common myth that a stem cell transplant is an operation where we surgically replace the bone marrow of the patient or inject the stem cells directly back into the bone. But the actual procedure itself is more like a blood transfusion, and not as dramatic as it may seem..

Stem cells are slowly injected back into the patient’s bloodstream, and these stem cells are then able to find their way back into the bone marrow to start regenerating and making new blood cells..

The pictures below show the process of infusion of stem cells using cells which had been stored in advance and re-infused into a patient.




A Bone Marrow Transplant and a blood Stem Cell Transplant are similar procedures that are used to treat patients with blood diseases. Both aim to replace the cells in your bone marrow with healthy ones. The difference between the two is that a Bone Marrow Transplant utilises stem cells extracted from your bone marrow or a donor’s bone marrow. In comparison, a blood Stem Cell Transplant makes use of stem cells extracted from your bloodstream or a donor’s bloodstream.

Our doctor will determine which method is more suited to your condition and case. However, Stem Cell Transplants are the more common type of transplant, as opposed to Bone Marrow Transplants. This is due to several reasons, including:

  • Blood stem cells are more accessible than bone marrow, and donors prefer to donate via the bloodstream.
  • More cells can be collected from the bloodstream compared to a bone marrow harvest.
  • Blood counts tend to regenerate faster using blood stem cells compared with bone marrow.

In order to find a donor for a Stem Cell Transplant, DNA markers, known as Human Leukocyte Antigens (HLA), are taken into consideration. HLA markers are located on the surface of one’s white blood cells, and we inherit them from our biological parents. HLA typing is used to identify the best compatible donor for a patient.

In most cases, a fully-matched family donor is often the first choice donor for an allogeneic Stem Cell Transplant. If there are no fully-matched siblings, then alternative choices may include matched donors from the donor registry networks, haploidentical donors from the family, or even umbilical cord blood units from the cord blood registry network.

The first stage of recovery after a Bone Marrow Transplant typically takes 4 to 6 weeks. This is the period in which our transplant team will monitor you to see if engraftment has occurred.

Typically, patients remain in the hospital until their blood counts stabilise and the patient is fit and independent without any infective complications.

Full recovery after a Bone Marrow Transplant can take between 6 months to a year.

You will be expected to remain in the hospital for between 3 to 4 weeks following a Bone Marrow Transplant, depending on the type of transplant you received.

Several short-term and long-term complications of a Stem Cell Transplant can result in weight loss. Short term complications such as throat and mouth pain, along with vomiting or nausea, can make it difficult for patients to eat. Additionally, long term complications following a Stem Cell Transplant like graft-versus-host-disease (GVHD) may also result in weight loss.

Our transplant team will monitor your oral intake as well as weight through the transplant journey. A dietician is an important member of our transplant team who will regularly review and advise if additional nutritional support is required.

Bone marrow and blood Stem Cell Transplants are an effective form of treatment for many forms of advanced blood cancers. However, the specific success rates depend on the type of cancer, the stage of the underlying blood cancer, as well as the type of treatment required. Our team of doctors will work to provide you with a personalised treatment plan with estimated chances of response after reviewing your case.

Yes, it is possible to live a full and normal life following a Stem Cell Transplant. While it will take time for you to regain your regular level of activity, many patients start to feel stronger between 2 months to a year after their Stem Cell Transplant. However, patients should note that this is still the recovery period, and fatigue is to be expected.

There are a number of complications that can occur after a Stem Cell Transplant. These include both short term and long term complications.

Patients may experience short term complications such as mouth and throat pain, vomiting or nausea, infection, or graft-versus-host-disease (GVHD). Longer-term complications include disease relapse, GVHD, cardiac and hormonal changes, as well as secondary cancers.

Our transplant team will work closely with you through the different phases of your transplant to monitor, prevent and manage any such complications.

Long-term side effects following a Bone Marrow Transplant vary depending on several factors. For example, the type of transplant, pre-transplant chemotherapy, the patient’s age and health, and whether graft-versus-host-disease (GVHD) is present may all affect the potential side effects experienced by a patient.

Some possible long-term side effects include organ damage, reduced fertility, relapse, second cancer, cataracts, and hormonal changes.



The information on the Centre For Clinical Haematology website is intended for educational use.  It should not be considered or used as a substitute for medical advice, diagnosis or treatment from a qualified health professional.

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Posted by CFCH