Treating leukemia by transplanting blood stem cells

Leukemia is a general term that refers to many different types of blood cancers with different causes, different treatments, and different outcomes. Researchers are finding ways to cure leukemia. One of which is treating leukemia by transplanting blood stem cells.

normal blood (left) compared to leukemia (right)

Table of Contents

Introduction

As we grow, many of us get mutations that causes some of our blood stem cells to multiply faster than others. They then form their own distinct populations or ‘clones’ by the process clonal hematopoiesis. Too many white blood cells (leukocytes) grow and do not mature normally. In the most serious types of leukemia, these cells look like normal immature cells called blasts. But they remain in this state. Therefore, these blasts are not able to perform the functions of normal mature blood cells, which is to defend the body against infection and disease.

Leukemia can be grouped according to the danger of the disease. Also by the types of abnormal white blood cells.

  • Acute leukemia, a disease in which these cells grow rapidly and hence treatment should take place right away. They even suppress the formation of normal blood cells by accumulating in the bone marrow. Depending on the type of affected cells, this is usually classified as acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML)
  • Chronic Leukemia, sub-classified as either chronic lymphocytic leukemia (CLL) or chronic myeloid leukemia (CML). A disease in which these cells grow more slowly but still allow normal blood cell production. Therefore, the symptoms may be milder.

Both chronic and acute subtypes of leukemia may develop in early childhood. Then increases in rate as people get older.

Research

Researchers now know most of the gene mutations that are most likely to be present in any given type of leukemia. Studies continue to examine hematopoietic stem cells (HSCs) and what turns them (or their daughter cells) into leukemia cells. Present stem cell treatments for severe leukemia may include the application of a blood stem cell transplant (also known as a hematopoietic stem cell transplant. To reduce current restriction of HSC transplant, researchers are studying new approaches. These include the development of treatments with immune cells, ways to boost patient immunity, and ways to restore blood cell production more rapidly. Using either current or alternative sources of cells for the transplants.

Like in all treatments there are down sides, this transplant also brings challenges with it. The blood and immune system of the patient is weak enough to fight infections until the transplanted cells have regenerated the mature cells. This is due the chemotherapy before the transplant that destroys the patient’s blood and immune system.

Second major challenge is due to minor genetic differences that may exist between transplanted stem cells and the patient. Such differences leads to transplanted cell rejection or attacking the patient’s tissues. It is called graft-versus-host disease, and it can be fatal in extreme cases.

Thousands of leukemia patients worldwide have received successful transplants containing blood stem cells. Although these treatments still carry very serious risks, these risks have greatly decreased over the years. This has happened because researchers are still learning more on treating leukemia by transplanting blood stem cells.