Understanding Transplantation

A blood stem cell transplant is a life-saving treatment for people with serious blood diseases like leukemia or other blood disorders. It works by replacing unhealthy blood cells with healthy ones from a donor.

Collection – Healthy stem cells are collected from a donor’s bone marrow, blood, or umbilical cord blood.
Transplantation – The collected cells are given to the patient through a vein, similar to a blood transfusion.
Engraftment – The new stem cells travel to the patient’s bone marrow, where they start producing new blood cells, including red blood cells, white blood cells, and platelets.

This process requires a skilled medical team to monitor the patient before, during, and after the transplant. While it carries some risks, for many patients, a stem cell transplant is the best or only hope for survival.

The patient journey

Diagnosis and Treatment Planning

The journey of a patient undergoing a stem cell transplant involves several key steps. After being diagnosed with a blood disorder, doctors assess whether a stem cell transplant is the best treatment option. The options are:

- Autologous Transplant: The patient’s own stem cells are collected and later transplanted back after treatment.
- Allogeneic Transplant: Stem cells come from a donor. Doctors first check if a sibling is a match (there’s a 25% chance). If not, they search global registries to find an unrelated donor with compatible human leukocyte antigens (HLA).

(Pre)-Transplant Treatment

Initiating a Search for an Unrelated Donor
1. WMDA manages a global database.
2. The database includes unrelated adult volunteers and cord blood units.
3. Advanced algorithms (Hap-E Search and Atlas) match patient HLA types with potential donors or cord blood units globally.
4. Only authorised healthcare professionals have access to Search & Match Service.
Once a matched unrelated or related donor has been found
1. The donor is contacted for confirmation.
2. The donor undergoes a thorough medical evaluation.
3. Cleared donors proceed to stem cell collection for transplantation into the patient.
Pre-Transplant Treatment: The patient receives chemotherapy (and sometimes radiation) to destroy diseased cells and prepare the body for new stem cells.

Transplantation

Recovery

The Role of WMDA

WMDA (World Marrow Donor Association) plays a crucial role in connecting patients with matching donors worldwide. As the only global certification body in the field of stem cell donation and international exchange, WMDA:

Supports donor registries and cord blood banks access to a global and a diverse pool of donors and cord blood units.
Sets global standards to protect both donors and patients.
Ensures quality and safety in the donation and facilitation process.
Works to expand donor availability worldwide, so more patients can find a match.

Thanks to WMDA’s efforts, millions of donors worldwide are available for patients in need.

Risks of transplantation

A bone marrow, peripheral blood stem cell or umbilical cord blood transplantation is a medical procedure, and no procedure is risk-free. Patients should always consult their transplant physician about the associated risks. Outcomes have improved considerably thanks to collaboration between scientists, clinicians and nurses within scientific communities that collect data on procedures and analyse outcomes. Disease-free survival rates depend on various aspects, including disease stage and degree of HLA matching between donor and patient.

Infection: the risk of infection is increased after transplantation because the patient’s immune system is weak. Infections can be serious and may be caused by bacteria, viruses, fungi or yeast. The risk of infections decreases as the immune system recovers.

Graft vs. Host Disease: GvHD is a common complication for people who receive blood stem cells from a donor. It can vary from mild to life-threatening. In GvHD, the new blood stem cells attack the recipient’s body. Acute GvHD occurs within 90 to 100 days after transplantation; chronic GvHD occurs more than 90 to 100 days after.

Graft failure: this means that the new blood stem cells do not function properly. It can happen if the patient’s immune system rejects the new blood stem cells, if the number or quality of the transplanted cells was insufficient, or if the transplanted cells are damaged by infection or toxic substances after transplantation.

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