Stem cell transplantation is used for a range of blood cancers and non-cancerous disorders. Conditions may include acute and chronic leukemias, Hodgkin and non-Hodgkin lymphomas, multiple myeloma, myelodysplastic syndromes and certain plasma-cell disorders. It may also be used for conditions such as aplastic anemia, sickle cell disease, thalassemia, certain immune deficiencies and inherited metabolic disorders. The suitability of transplantation depends on the specific disease, its characteristics, available treatment options and the patient's overall health.

An autologous transplant uses the patient's own healthy blood-forming stem cells. These cells are collected and stored before intensive treatment and then returned to the patient to help restore bone marrow function. An allogeneic transplant uses stem cells from another person whose tissue characteristics are sufficiently compatible with the patient. Donor transplantation can provide an additional immune effect against certain diseases but also carries risks such as graft-versus-host disease. The choice depends on the disease and treatment goals.

Before transplantation, the team performs a detailed assessment to determine whether the procedure is likely to be safe and beneficial. Evaluation may include a review of medical history, physical examination, blood tests, imaging, assessment of heart, lung and other organ function, and sometimes a bone marrow examination. The team may also evaluate nutritional and psychosocial factors and assess the status of the underlying disease. These investigations help identify potential risks and determine the most appropriate conditioning and transplant approach.

For an allogeneic transplant, the team looks for a donor whose tissue characteristics are sufficiently compatible with those of the patient. This matching process helps reduce complications and improve the likelihood that the transplanted cells will function successfully. Potential donors may include family members or unrelated donors, and stem cells may come from blood, bone marrow or, in selected circumstances, umbilical cord blood. The transplant team evaluates available donor options and selects the most suitable source based on the patient's disease and individual circumstances.

Recovery generally progresses through several stages: conditioning treatment, stem cell infusion, engraftment and longer-term immune and blood-cell recovery. After infusion, the transplanted stem cells travel to the bone marrow and begin producing new blood cells, a process known as engraftment. This usually takes several weeks, during which patients may require close monitoring, medicines and sometimes blood or platelet transfusions. Recovery continues well beyond engraftment, with regular follow-up to monitor blood counts, infections, complications and the underlying disease.

After transplantation, the immune system needs time to recover, so patients may have an increased risk of infections and other complications. Depending on the transplant type, medicines may be prescribed to prevent infections or, after an allogeneic transplant, reduce the risk of graft-versus-host disease. Regular blood tests and clinical assessments are essential during recovery. Patients may also need guidance on diet, activity, hygiene and avoiding infection risks. Follow-up continues long term because some transplant-related complications can develop months or even years later.