When does someone need stem cells?

The most common disease for which stem cell transplantation is used is leukemia. Stem cell transplantation is often considered a last resort for the patient.

Where can I register?

Leukemia

Leukemia is a collective term used for different types of blood cancer. There are four types of leukemia:  

  • Acute Myeloid Leukemia (AML)
  • Chronic Myeloid Leukemia (CML)
  • Acute Lymphocytic Leukemia (ALL) 
  • Chronic Lymphocytic Leukemia (CLL) 

Every year, leukemia affects hundreds of thousands of people around the world. Stem cell donors can give leukemia patients a chance to make a full recovery from this disease. For this to happen, there must be a match between the donor's and the patient's tissue typing. The chance of two people being a match is very small, so it is important to register as many stem cell donors as possible.  

Compromised blood cell production 

Our blood is made up of different types of blood cells, which start their life as blood-forming stem cells in our bone marrow. These stem cells can develop into red blood cells, white blood cells (immune cells) or platelets. This is a never-ending process which ensures that old, ‘worn-out’ blood cells are replaced with new ones. 

In a patient with leukemia, the production of blood cells from stem cells works differently. In a leukemia patient's body, there is a disrupted growth of immature cells. This compromises the production of normal blood cells in the bone marrow and can lead to life-threatening situations as a result of: 

  • Infections (because there are not enough functional white blood cells)
  • Bleeding (because of a shortage of platelets)
  • Oxygen deprivation in healthy tissues and organs (because there are not enough red blood cells) 

The disrupted cell growth and division are caused by damage to the genetic material of a blood stem cell, which causes it to divide uncontrollably.  

Treatment

What treatment is required depends on the type of leukemia. In many cases, patients are treated with chemotherapy, often combined with radiotherapy. The chemotherapy destroys the leukemia cells. During radiotherapy, specific parts of the body are irradiated, which causes localized damage to the genetic material of the cells. This prevents these cells from dividing any further.  

Stem cell transplantation 

If the treatment is insufficiently successful or if the patient has a high risk of relapse, the next step may be a stem cell transplantation. Administering healthy stem cells from a stem cell donor gives the patient a chance to fully recover from their disease.  

Before a patient can undergo a stem cell transplantation, their own bone marrow immune system must first be ‘deactivated'. This is done by treating the patient with a dose of chemotherapy and radiotherapy high enough to irreparably damage their bone marrow. Without this treatment, a patient's immune system will attack and destroy the donor cells, which means the transplantation fails. 

The donated stem cells are administered intravenously and will move to the patient's bone marrow on their own. Once there, they will start to multiply and later begin producing healthy blood cells. It takes around two weeks before it can be determined in a laboratory that the new stem cells are successfully doing their job. 

Healing 

Besides producing new stem cells and blood cells, the donor cells can also identify sick leukemia cells. When donor cells identify sick cells, they can destroy them and give the patient a chance to make a full recovery from their disease. 

 

Different types of leukemia 

 

What is the difference between acute and chronic leukemia? 

In acute leukemia, the precursor cells in a patient's bone marrow do not fully mature. These ‘immature’ cells continue to divide, causing them to accumulate in the bone marrow. This creates a shortage of normal (mature) white blood cells in the blood.  

In chronic leukemia, the bone marrow cells only partially mature and these cells do not function normally. The abnormal cells are unable to combat infections effectively. Ultimately, these cells will displace the normal white blood cells. Chronic leukemia can remain dormant in a patient for years.  

What is the difference between Acute Myeloid Leukemia (AML) and Acute Lymphocytic Leukemia (ALL)?

The difference between Acute Myeloid Leukemia and Acute Lymphocytic Leukemia results from the type of cell in which the abnormality occurs.  

AML (Acute Myeloid Leukemia) originates in the ‘immature’ myeloid precursor cell. It causes the cell to stop producing mature red blood cells, platelets and certain white blood cells. This form of leukemia is more common in adults or elderly people.  

In ALL (Acute Lymphocytic Leukemia), the lymphocytes do not mature fully before leaving the bone marrow. A lymphocyte is a specific type of white blood cell. As these do not mature fully, it leads to a shortage of well-functioning white blood cells of this type.  This form of leukemia is more common in younger people. 

Other conditions 

Besides leukemia, a stem cell transplantation can also be used to treat other diseases. Examples include: 

  • Myelofibrosis
  • Sickle cell anemia
  • Thalassemia
  • MDS (Myelodysplastic syndrome)
  • Aplastic anemia